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Glossary TermDescriptions or DefinitionsRelevant Link (usually Wikipedia)
1A, C, G, TAbbreviations for each of the four possible nitrogenous bases in each nucleotide of a DNA sequence, including adenine (A), cytosine (C), guanine (G), and thymine (T).(not applicable)
2A, C, G, UAbbreviations for each of the four possible nitrogenous bases in each nucleotide of an RNA sequence, including adenine (A), cytosine (C), guanine (G), and uracil (U).(not applicable)
3aaRS (aminoacyl-tRNA synthetase)Abbreviation for amino-acyl RNA synthetase enzymes. These enzymes link specific amino acids to specific transfer RNA (tRNA) molecules. In this way, amino acids that correspond to particular codons in DNA and messenger RNA (mRNA) are brought to the ribosomes, where they are chemically bonded, in the correct sequence, in each growing protein chain, during protein synthesis.https://en.wikipedia. org/wiki/ Aminoacyl_tRNA_ synthetase
4AbiogenesisInformally known as the origin of life, it is the natural process by which life arises from nonliving matter, such as simple organic compounds. The transition from nonliving to living entities was a gradual process of increasing complexity.https://en.wikipedia. org/wiki/ Abiogenesis
5AbstractA succinct formal summary of the contents of a published scientific journal article, frequently included at the beginning of the article. Publishers often provide free access to Abstracts.(not applicable)
6Accessory pigmentsLight-absorbing compounds, found in photosynthetic organisms, that work in conjunction with chlorophyll a. They include other forms of this pigment, such as chlorophyll b, c, or d.https://en.wikipedia. org/wiki/ Accessory_pigment
7AcetogenA microorganism that generates acetate as an end product of respiration without oxygen. There are also what are thought to be genuine acetogens, known as “homoacetogens”. These can produce biochemical reactions from two molecules of carbon dioxide and four molecules of molecular hydrogen.https://en.wikipedia. org/wiki/Acetogen
8AcetogenesisA process through which acetate is produced from carbon dioxide and an electron source, with no requirement for oxygen. This takes place via biochemical reactions.https://en.wikipedia. org/wiki/ Acetogenesis
9ActinSubunit containing alpha and/or beta actin protein chains. Actin subunits are often found as polymerized actin microfilaments that make up part of the cytoskeleton of a cell.https://en.wikipedia. org/wiki/Actin
10AdaptationIn biology, there are three related meanings. Firstly, it is the dynamic evolutionary process that fits organisms to their environment, enhancing their evolutionary fitness. Secondly, it is a state reached by the population during that process. Thirdly, it is an observable trait, with a functional role in each individual organism, that is maintained and has been evolved by Natural Selection.https://en.wikipedia. org/wiki/Adaptation
11AdaptationsObservable traits, with functional roles in each individual organism, that are maintained and have been evolved by Natural Selection.https://en.wikipedia. org/wiki/Adaptation
12Adaptive immune systemSpecialized cells such as T cells, B cells and accessory cells, and members of the immunoglobulin superfamily of genes, that interact and bind to specific antigens and proactively increase the numbers of circulating T cells and B cells that bind to particular antigens, thereby optimizing secondary immune responses. Also responds to self-antigens by removing or suppressing T cell and B cells that respond to those self-antigens (immune tolerance).https://en.wikipedia. org/wiki/ Adaptive_immune_ system
13Adenosine triphosphate (ATP)A “high-energy” compound widely used as a readily accessible energy source for active cellular processes. Most energy is captured by breaking the covalent bond between the second and third phosphates attached to the sugar. These bonds represent high potential energy because repulsion of the electron clouds make them highly unstable.https://en.wikipedia. org/wiki/ Adenosine_ triphosphate
14Algae (algal)An informal term for a large, diverse group of photosynthetic eukaryotic organisms that are not necessarily closely related. Included organisms range from unicellular microalgae genera, such as Chlorella and the diatoms, to multicellular forms, such as the giant kelp, a large brown alga which may grow up to 50 m in length.https://en.wikipedia. org/wiki/Algae
15AlkalineAn aqueous solution that has a pH above7.0 due to a lower concentration of protons (hydrogen ions) than found in pure water.https://en.wikipedia. org/wiki/Alkali
16Alkaline hydrothermal vent (Lost City Hydrothermal Field)The first alkaline deep-sea hydrothermal vent, known as the Lost City, was discovered on the mid-Atlantic sea floor in 2,000. Distinguished from high-temperature hydrothermal vents known as black smokers, alkaline vents are formed by serpentinization, in which olivine (magnesium iron silicate) and similar rock on the seafloor reacts with water. This produces large volumes of hydrogen. Precipitation reactions between the warm (45−90C) alkaline (pH 9−11) vent fluids and the colder, more acidic seawater create tall, porous calcium carbonate chimneys containing embedded metals and minerals. It is thought that proton gradients generated by similar, ancient vents provided the energy required for the metabolic reactions that led to the origin of life.https://en.wikipedia. org/wiki/ Hydrothermal_vent
17AlleleA variant form of a given gene, resulting from DNA sequence differences. In protein-coding genes, may result in production of a variant amino acid sequence, or failure to produce a functional protein.https://en.wikipedia. org/wiki/Allele
18Allele frequencyThe relative frequency of an allele (a variant) of a specific gene in a population. Alleles are represented by specific DNA sequences at particular chromosomal positions. The allele frequency can be expressed as a fraction or percentage.https://en.wikipedia. org/wiki/ Allele_frequency
19Alpha-helixA common motif in the secondary structure of proteins. Also, a helix in which the N−H backbone donates a hydrogen bond to the CO groups of the amino acid.https://en.wikipedia. org/wiki/ Alpha_helix
20Alpha-proteobacteriaA class of bacteria in the Proteobacteria phylum. Its members are highly diverse and possess few commonalities, but share a common ancestor.https://en.wikipedia. org/wiki/ Alphaproteobacteria
21Amino acidOrganic compounds containing amine and carboxyl functional groups, along with a side chain specific to each amino acid. The key elements are carbon, hydrogen, oxygen, and nitrogen.https://en.wikipedia. org/wiki/ Amino_acid
22Amino acid sequenceThe sequence of amino acids in a protein chain, or the sequence that can be predicted from analysis of a specific protein-coding DNA or RNA segment.https://en.wikipedia. org/wiki/ Protein_primary_ structure
23Amino groupFunctional group consisting of a nitrogen atom attached to carbon or hydrogen atoms.https://en.wikipedia. org/wiki/ Amino_acid
24Amplify (PCR)To amplify is to use PCR to generate a large number of identical copies of nucleic acid target sequences, starting with a small number of DNA or RNA template molecules. PCR is a powerful, rapid, and widely-used technique in biotechnology.https://en.wikipedia. org/wiki/ Polymerase_chain_ reaction
25AnimalA member of the animal kingdom. Animals represent one of the three kingdoms of multicellular eukaryotic organisms, the others being plants and fungi.https://en.wikipedia. org/wiki/Animal
26AnthropomorphicThe attribution of human traits, emotions, or intentions to nonhuman entities. Anthropomorphism is considered to be an innate tendency of human psychology.https://en.wikipedia. org/wiki/ Anthropomorphism
27Antibiotic resistanceAn evolved insensitivity to one or more antibiotics, which takes place by a variety of known mechanisms, and represents a serious threat to the global human population.https://en.wikipedia. org/wiki/ Antimicrobial_ resistance
28AntibodyOne of an extremely diverse set of proteins produced by B cells. The variable regions of these proteins can bind to a very large number of distinct antigens in a highly selective manner.https://en.wikipedia. org/wiki/Antibody
29AnticodonThree-base triplet on transfer RNA molecule that base-pairs with messenger RNA codon during synthesis of a protein chain (translation). Assures that the amino acid will be incorporated into the growing chain in the correct sequence, at the ribosome.https://en.wikipedia.org/wiki/Transfer_RNA
30Antigen(immunology)A molecule capable of inducing an immune response in the host organism.https://en.wikipedia. org/wiki/Antigen
31Antigen-presenting cellAlso known as an accessory cell, it is a cell that displays a molecule which will induce an immune response. It is complexed with cell surface proteins essential for the immune system to recognize foreign molecules.https://en.wikipedia. org/wiki/Antigen-presenting_ cell
32AntiporterA transporter, which in modern cells consists of a transport protein embedded in a biological membrane. Antiporters move two different types of molecules in opposite directions. This may take advantage of the energy flux of one type of molecule to move the other type in the opposite direction.https://en.wikipedia. org/wiki/Antiporter
33ApoptosisA type of programmed-cell death that represents a normal part of development and also provides a way of eliminating cells that are dangerous because they are infected or cancerous.https://en.wikipedia. org/wiki/Apoptosis
34Aqueous solutionA solution in which the solvent that dissolves a solute is water. Solutes can be liquid, solid or gas. The cytoplasm of all cells mostly consists of an aqueous solution that is packed with large numbers of macromolecules and other substances.https://en.wikipedia. org/wiki/ Aqueous_solution
35Archaea(archaebacteria)One of the two domains of prokaryotic organisms, which can be distinguished from bacteria by comparison of their genome, metabolism, and cell wall structure. Reported in 1977 by Carl Woese and colleagues.https://en.wikipedia. org/wiki/Archaea
36AstrobiologySearches for empirical evidence and principles related to past or present extraterrestrial life forms.https://en.wikipedia. org/wiki/ Astrobiology
37AtomThe smallest constituent unit of ordinary matter that has the properties of a chemical element. Every solid, liquid, gas, and plasma is composed of atoms.https://en.wikipedia. org/wiki/Atom
38Atomic nucleiRelatively small dense core of atoms containing positively charged protons and neutrally charged neutrons.https://en.wikipedia. org/wiki/ Atomic_nucleus
39ATPA complex organic chemical that provides energy to drive many processes in living cells. It is also a precursor to DNA and RNA, and is used as a coenzyme.https://en.wikipedia. org/wiki/ Adenosine_ triphosphate
40ATP synthaseAn enzyme that synthesizes ATP (adenosine triphosphate) by transforming the energy of protons that flow through the enzyme to equalize a proton gradient.https://en.wikipedia. org/wiki/ ATP_synthase
41ATP synthesisSynthesis of adenosine triphosphate, a widespread energy currency of all living cells.https://en.wikipedia. org/wiki/ ATP_synthase
42Autonomous specification (determinate cleavage)A type of embryonic cleavage in which cytoplasmic determinants combined with cell lineage define patterns of cell differentiation, rather than intercellular communication between neighboring embryonic cells (blastomeres).https://en.wikipedia. org/wiki/ Cleavage_(embryo)
43AutosomeA chromosome that is not a sex chromosome. Diploid organisms have pairs of autosomes that are similar in form and DNA sequence. Each gene in a pair of autosomes may contain the same alleles or different alleles.https://en.wikipedia. org/wiki/Autosome
44AutotrophAn organism that captures energy from inorganic chemicals or sunlight and use raw materials such as carbon dioxide and minerals to build their own organic compounds.https://en.wikipedia. org/wiki/Autotroph
45B cellA specialized white blood cell, the part of the adaptive immune system that produces specific antibodies.https://en.wikipedia. org/wiki/B_cell
46Bacteria (eubacteria)Single-celled organisms from one of the two domains of prokaryotes. The other domain is archaea.https://en.wikipedia. org/wiki/Bacteria
47BacteriophageA virus that infects and replicates within bacteria and archaea. Bacteriophages are composed of proteins that encapsulate a DNA or RNA genome.https://en.wikipedia. org/wiki/ Bacteriophage
48Baldwin effectThe effect of a learned behavior on evolution. James Mark Baldwin hypothesized an organism’s ability to learn new behaviors could affect its reproductive success. This would increase the probability that half of its genome would be passed on to the next generation. Any genes that contributed to that ability to learn could be passed on. This could increase the learning capabilities in the gene pool. The Baldwin effect was consistent with other empirical data and was considered part of the Modern Synthesis.https://en.wikipedia. org/wiki/ Baldwin_effect
49Base (nitrogenous)One of four different nitrogen-containing organic ring structures found in nucleotides of DNA or RNA (see A, C, G, T and A, C, G, U, respectively). Nitrogenous bases pair with complementary bases by hydrogen bonding; A pairs with T or U and G pairs with C.https://en.wikipedia. org/wiki/ Nitrogenous_base
50base-pairingAs a verb, refers to hydrogen bond formation between complementary pairs of nitrogenous bases in strands of DNA and/or RNA. As a noun, referred to pair of hydrogen-bonded nitrogenous bases. In DNA, A pairs with T and G with C; in RNA, A pairs with U and G pairs with C.https://en.wikipedia. org/wiki/Base_pair
51Basic research (fundamental research)Research intended to expand and improve knowledge concerning natural phenomena, usually without a specific or immediate application in mind.https://en.wikipedia. org/wiki/ Basic_research
52Beta-pleated sheetA common motif of regular secondary structure in proteins. They consist of beta strands connected laterally by two or three backbone hydrogen bonds. This forms the twisted, pleated sheet.https://en.wikipedia. org/wiki/Beta_sheet
53BicoidA maternal effect gene whose protein concentration gradient patterns the anterior−posterior (A−P) axis during Drosophila (fruitfly) embryogenesis.https://en.wikipedia. org/wiki/Bicoid_ (gene)
54Binary bitsUnits of digital information used in computer data. Has two alternative states, designated as 0 or 1, representing electrical states that switch between “off” or “on”. Sequences of bits can encode larger units of information, such as ASCII characters.https://en.wikipedia. org/wiki/Bit
55BiofilmAny consortium of microorganisms exchanging nutrients, in which cells stick to each other and often also to a surface. These adherent cells become embedded within a slimy extracellular matrix.https://en.wikipedia. org/wiki/Biofilm
56Biological evolutionThe empirically proven natural process of change in all living things on Earth. Natural Selection is one of the most fundamental mechanisms that account for biological evolution, but it is not the only relevant mechanism involved. Biological evolution includes the precellular molecular changes that led to the origin of life on Earth, as well as subsequent changes in the complexity of structures and functions in all living cells and organisms. Evolution is also the fundamental process responsible for the Origin of Species, as pointed out by Charles Darwin in 1859, in the context of Natural Selection.https://en.wikipedia.org/wiki/Evolution
57Biological membraneAn enclosing or separating membrane consisting of a lipid bilayer that acts as a selectively permeable barrier within or surrounding a living cell.https://en.wikipedia. org/wiki/ Biological_ membrane
58Biological organizationThe hierarchy of complex biological structures, functions, and systems, that helps to define the complexity of life in terms of simpler ideas. This is a fundamental premise for numerous areas of scientific research.https://en.wikipedia. org/wiki/ Biological_ organisation
59Biomass (ecology)The mass of living biological organisms in a given area or ecosystem at a given time. Biomass can refer to species biomass, which is the mass of one or more species, or to community biomass, which is the mass of all species in the community. It can include microorganisms, plants, or animals. The mass can be expressed as the average mass per unit area, or as the total mass in the community.https://en.wikipedia. org/wiki/Biomass
60Bithorax complexA group of homeotic genes in fruitflies (Drosophila melanogaster) which control the differentiation of the abdominal and posterior thoracic segments, located on chromosome III. The name is derived from the fact that when these genes are mutated, the third thoracic segment becomes a repeat of the second thoracic segment, creating what is essentially a second thorax.https://en.wikipedia. org/wiki/ Bithorax_complex
61Body planA body plan is a set of morphological features common to many members of a phylum of animals. Refers to diverse vertebrate and invertebrate phyla.https://en.wikipedia. org/wiki/Body_plan
62Boveri−Sutton chromosomal theory of inheritanceA now well-supported unifying theory of genetics that identifies chromosomes as the carriers of genetic material.https://en.wikipedia.org/wiki/Boveri% E2%80%93Sutton_ chromosome_theory
63buoyant density centrifugation (biology)A separation technique in which a dense solution is centrifuged at high speed so that substances form bands equivalent to their density. Was commonly used in recombinant DNA technology to separate cloned plasmid DNA from bacterial DNA.https://en.wikipedia. org/wiki/ Buoyant_density_ centrifugation
64Cambrian explosionA relatively short period starting approximately 541 million years ago and lasting about 20−25 million years, when most major animal phyla appeared in the fossil record. It resulted in the divergence of most modern metazoan phyla and diversification of other organisms.https://en.wikipedia. org/wiki/ Cambrian_explosion
65Capillary actionThe ability of a liquid to flow in narrow spaces without external forces like gravity. It is the result of intermolecular forces between the liquid and surrounding solid surfaces.https://en.wikipedia. org/wiki/ Capillary_action
66CarbohydrateMacromolecule composed of carbon, hydrogen, and oxygen atoms. Includes simple sugars or polymers of sugars such as cellulose, glycogen, starch, and chitin.https://en.wikipedia. org/wiki/ Carbohydrate
67Carbon fixationCapture of carbon dioxide by photosynthetic organisms, from which organic compounds are synthesized.https://en.wikipedia. org/wiki/ Carbon_fixation
68CatalystAn inorganic substance, a co-factor or an enzyme that lowers the activation energy for a chemical reaction, thereby increasing its speed. Catalysts are typically not consumed or destroyed by chemical reactions, so they are reusable.https://en.wikipedia. org/wiki/Catalysis
69Catalytic (catalyst)An entity or process involving a catalyst. A catalyst is an inorganic substance, a co-factor or an enzyme that lowers the activation energy for a chemical reaction, thereby increasing its speed. Catalysts are typically not consumed or destroyed by chemical reactions, so they are reusable.https://en.wikipedia. org/wiki/Catalysis
70CD4“Helper” T cells that interact with other T cells, B cells, and antigen presenting cells in the adaptive immune system to regulate immune responses.https://en.wikipedia. org/wiki/CD4
71CD8“Cytotoxic” T cells that can eliminate infected or cancerous cells. May also be associated with suppression of immune responses.https://en.wikipedia. org/wiki/CD8
72cDNA(complementary DNA)Complementary DNA strand synthesized from an RNA template by reverse transcriptase enzyme. Associated with retroviruses and widely used in biotechnology.https://en.wikipedia. org/wiki/ Complementary_ DNA
73CellThe fundamental semi-autonomous unit found in all forms of unicellular or multicellular life, including the three domains of bacteria, archaea, and eukaryotes. All cells contain a cell membrane, chromosomes containing DNA, and ribosomes that are the sites of protein synthesis.https://en.wikipedia. org/wiki/ Cell_(biology)
74Cell adhesionBinding of two or more cells, often in multicellular organisms, which usually involves specific specialized proteins and cell junctions.https://en.wikipedia. org/wiki/ Cell_adhesion
75Cell biologyThe broad interdisciplinary fields of biology that study various aspects of cell structure and function.https://en.wikipedia. org/wiki/ Cell_biology
76Cell cycleA regulated process by which eukaryotic cells grow, replicate their genetic material and divide in an orderly fashion, in response to internal and external signals. The cell cycle includes stages of growth and DNA replication designated G1, S, and G2, mitosis in which chromosomeshttps://en.wikipedia. org/wiki/Cell_cycle
77Cell divisionThe division of parent cells into daughter cells. Cell division in prokaryotes is called binary fission. Cell division in eukaryotes includes mitotic division, which produces genetically identical daughter cells, and meiosis in which diploid germ line cells divide into haploid cells that develop into sperm or egg cells, known as sex cells, in which the daughter cells are genetically diverse.https://en.wikipedia. org/wiki/ Cell_division
78Cell fractionationThe process used to separate cellular components while preserving individual functions of each component.https://en.wikipedia. org/wiki/ Cell_fractionation
79Cell membrane (plasma membrane)Biological membrane that separates the interior of all types of cells from the outside environment. Consists of two lipid layers with embedded proteins and other molecules. Cell membrane designation refers to outer membrane, which distinguishes that biological membrane from internal lipid membranes which are also widespread.https://en.wikipedia. org/wiki/ Cell_membrane
80Cell motilityA general term referring to various types of cell movement, migration, and shape changes, often mediated by the internal cytoskeleton and/or by cilia or flagella which can propel a cell through an external fluid medium. Cell migration often involves signals from extracellular materials as well as changes in cell adhesion.https://en.wikipedia. org/wiki/ Cell_migration
81Cell signalingA general term referring to local and long-distance signals passed between cells that coordinate their activities. In multicellular organisms, local signals may involve physical contact between cell surface proteins, including receptors, or short-range diffusion of signals known as paracrine signals. Long-range signaling often involves hormones secreted by glands, such as endocrine glands.https://en.wikipedia. org/wiki/ Cell_signaling
82Cell-free preparationA laboratory preparation that includes specific isolated or fractionated materials from cells, which often continue to carry out particular functions that can be isolated, tagged, and studied by observations and experiments under controlled conditions.https://en.wikipedia. org/wiki/Cell-free_system
83Cell-surface receptorA protein on the cell surface that receives and responds to signals from other cells or from the environment. Often, eukaryotic cell surface receptors extend through the cell membrane and respond to signals by triggering internal signal transduction pathways involving events in the cytoplasm and nucleus of the cell.https://en.wikipedia. org/wiki/ Cell_surface_ receptor
84Cellular differentiationThe process whereby initially flexible embryonic stem cells become specialized and develop into specific cell types with specialized patterns of gene expression.https://en.wikipedia. org/wiki/ Cellular_ differentiation
85Cellular metabolismThe set of life-sustaining chemical transformations within the cells of organisms. Its main purposes are in the breakdown (catabolism) and synthesis (anabolism) of macromolecules, and in energy transformations. Additionally, metabolism eliminates nitrogenous wastes.https://en.wikipedia. org/wiki/Metabolism
86Cellular slime moldA type of fungus that has both solitary and aggregated multicellular stages in its life cycle.https://en.wikipedia. org/wiki/ Slime_mold
87Central dogma of molecular geneticsA tongue-in-cheek expression attributed to Francis Crick, which hypothesizes that genetic information can flow from DNA to RNA to proteins but not the other way around. Today, we know that these macromolecules are parts of a complex adaptive system that interact in complex ways. For example, transcription factors are proteins that control the expression of genes by binding to DNA, which means that genetic information is flowing from proteins back to DNA.https://en.wikipedia. org/wiki/ Central_dogma_of_ molecular_biology
88ChaperoninProteins that provide favorable conditions for the correct folding of other proteins. This prevents the formation of clusters and misfolding, which in turn prevents diseaseshttps://en.wikipedia. org/wiki/Chaperonin
89Charged (electric)An entity that has a static positive or negative charge, usually associated with gains or losses of electrons.https://en.wikipedia. org/wiki/ Electric_charge
90Charles DarwinThe famous 19th century biologist who published The Origin of Species in 1859 which correctly hypothesized that biological evolution of adaptations and of species depend on Natural Selection.https://en.wikipedia. org/wiki/ Charles_Darwin
91Chemical mutagensChemicals that speed up the rate of changes in DNA sequences over the spontaneous rate.https://en.wikipedia. org/wiki/Mutagen
92ChemoautotrophicOrganisms that use chemical energy from the environment to fix carbon and build macromolecules.https://en.wikipedia. org/wiki/ Chemotroph
93ChloroplastOrganelles, or specialized compartments, in plant and algal cells. The main role is to conduct photosynthesis.https://en.wikipedia. org/wiki/Chloroplast
94ChoanoflagellateA group of free-living unicellular and colonial flagellate eukaryotes considered to be the closest living relatives of the animals.https://en.wikipedia. org/wiki/ Choanoflagellate
95ChromatinA complex of DNA, RNA, and protein found in eukaryotic cells. It plays various roles in the structural integrity of the DNA, in cell division, in preventing DNA damage, and in regulating gene expression and DNA replication.https://en.wikipedia.org/wiki/Chromatin
96ChromosomeA long DNA molecule often complexed with proteins and RNA sequences that represents part or all of the genetic material (genome) of an organism.https://en.wikipedia. org/wiki/ Chromosome
97Classes of organic compoundsOrganic compounds are classified on the basis of the presence or absence of specific structural formulas and functional groups.https://en.wikipedia. org/wiki/ Organic_compound
98Classical DarwinismA theory of biological evolution developed by the English naturalist Charles Darwin (1809–1882) and others, stating that all species of organisms arise and develop through the Natural Selection of small, inherited variations that increase the individual’s ability to compete, survive, and reproduce. Also called Darwinian theory.https://en.wikipedia. org/wiki/Darwinism
99Cleavage (embryo)Division of cells during development of an embryo. Usually begins with a fertilized egg (zygote) in sexually reproducing organisms.https://en.wikipedia. org/wiki/ Cleavage_(embryo)
100Cloning (cellular)The process of producing genetically identical individuals of an organism from identical cells, either naturally or artificially.https://en.wikipedia. org/wiki/Cloning
101Cloning (molecular)Production of large numbers of identical copies of DNA or RNA. Often refers to recombinant DNA technology.https://en.wikipedia. org/wiki/ Molecular_cloning
102Co-dominanceAlleles that simultaneously produce distinct visible phenotypes in organisms. For example, A, B, and AB blood types are caused by the presence of co-dominant alleles, and represent proteins that act as distinct cell-surface antigens on red blood cells.https://en.wikipedia. org/wiki/ Dominance_ (genetics)
103CodonA nucleotide triplet in DNA or RNA that is associated with the addition of a particular amino acid (or a start or stop signal) during translation of new protein chains.https://en.wikipedia. org/wiki/ Genetic_code
104CoevolutionOccurs when two or more species reciprocally affect each other’s evolution.https://en.wikipedia. org/wiki/ Coevolution
105Colonial (colony, biology)Two or more individuals of the same species living in close proximity to each other.https://en.wikipedia. org/wiki/ Colony_(biology)
106CommensalismA long-term biological interaction in which members of one species gain benefits while members of another species are neither benefited nor harmed.https://en.wikipedia. org/wiki/ Commensalism
107Complementary DNA (cDNA)DNA synthesized from a single-stranded RNA template. This reaction is catalyzed by an enzyme called reverse transcriptase which generates a single DNA strand that is complementary to an RNA strand used as the template.https://en.wikipedia. org/wiki/ Complementary_ DNA
108Complex adaptive systemA system in which a perfect understanding of individual parts does not convey a perfect understanding of the whole system’s behavior. Complex adaptive systems often change or evolve over time.https://en.wikipedia. org/wiki/ Complex_adaptive_ system
109Complex organization (biological)The hierarchy of complex biological structures and systems that define life using a reductionist approach. Each level in the hierarchy represents an increase in organizational complexity, with each “object” being primarily composed of the previous level’s basic unit. The basic principle behind the organization is the concept of emergence—the properties and functions found at a hierarchical level are not present and irrelevant at the lower levels.https://en.wikipedia. org/wiki/ Biological_ organisation
110Complexity (complex adaptive system)Biological complexity can be described as a special type of complex adaptive system, that is, a system in which a perfect understanding of the individual parts does not automatically convey a perfect understanding of the whole system’s behavior. Biological systems are complex in that they are dynamic networks of interactions. They are adaptive in that the individual and collective behavior mutate, self-organize, and evolve under Natural Selection.https://en.wikipedia. org/wiki/ Complex_adaptive_ system
111Composite biological organizationRefers to composite cells, genomes, or organisms. Examples of composite cells are eukaryotic cells which have evolved by endosymbiosis. Examples of composite genomes are bacteria and archaea that frequently exchange genetic material by horizontal gene transfer. Examples of composite organisms are lichens which are composed of both algal and fungal components.https://en.wikipedia. org/wiki/ Biological_ organisation
112Composite cell (symbiogenesis)Eukaryotic cells are composite cells because they evolve by symbiogenesis (endosymbiosis) from prokaryotic forebears. This is well-supported by a consilience of empirical evidence. The composition of the genome and presence of organelles such as mitochondria and/or chloroplasts that retain their own separate chromosomes represent some of these lines of evidence.https://en.wikipedia. org/wiki/ Symbiogenesis
113Composite genomeGenome composed of genetic material from more than one species, usually arising in evolution by lateral gene transfer or endosymbiosis.(not applicable)
114Composite organismOrganisms such as lichens that have cellular structures composed of two or more species of organisms.https://en.wikipedia. org/wiki/Organism
115ConcentrateA form of substance which has had the majority of its base component removed.https://en.wikipedia. org/wiki/ Concentrate
116Conditional specificationA type of embryonic cleavage in which the differentiation of cells remains flexible and depends on intercellular communication between neighboring embryonic cells (blastomeres).https://en.wikipedia. org/wiki/ Cleavage_(embryo)
117ConsciousnessConsciousness is the state or quality of awareness or of being aware of an external object or something within oneself. It has been defined variously in terms of sentience, awareness, qualia, subjectivity, the ability to experience or to feel, wakefulness, having a sense of selfhood or soul, the fact that there is something “that it is like” to “have” or “be” it, and the executive control system of the mind. Despite the difficulty in definition, many philosophers believe that there is a broadly shared underlying intuition about what consciousness is.https://en.wikipedia. org/wiki/ Consciousness
118ConsilienceThe principle that evidence from independent sources can converge on strong conclusions. When multiple sources of evidence are in agreement, the conclusion can be very strong.https://en.wikipedia. org/wiki/Consilience
119Consumer (heterotroph)An organism that must consume (internalize) and metabolize organic compounds from other organisms to obtain energy and nutrients for synthesizing macromolecules.https://en.wikipedia. org/wiki/ Heterotroph
120Control of gene expressionRegulation of production of gene products, which sometimes, but not always, involves control of transcription by transcription factors.https://en.wikipedia. org/wiki/ Regulation_of_ gene_expression
121Covalent bondA strong chemical bond between atoms that involves sharing of electron pairs between atoms. Electron sharing adds to stability with hybrid orbitals that have equivalent of full outer shell. Separation of the atoms often requires chemical reaction that breaks the bond.https://en.wikipedia. org/wiki/ Covalent_bond
122CreationismA religious belief that the universe and life originated from specific acts of divine creation. Usually includes human origins. This opposes the scientific conclusion that the universe and life arose through natural processes such as the Big Bang and Natural Selection, respectively. Often masquerades as a scientific theory.https://en.wikipedia. org/wiki/ Creationism
123CRISPRAn abbreviation of Clustered Regularly Interspaced Short Palindromic Repeats. A family of DNA sequences in bacteria and archaea.https://en.wikipedia. org/wiki/CRISPR
124Cross-hybridization (DNA or RNA)Formation of a double-stranded hybrid nucleic acid segment or molecule in which one strand of DNA and/or RNA is derived from one species (or individual) and the other strand is derived from another. May indicate homology (conservation and common origin) of sequences or may occur between repetitive sequences.https://en.wikipedia. org/wiki/ Hybridisation
125Crossing-over (crossovers)Exchanges of genetic material between two homologous chromosomes that results in recombinant chromosomes during sexual reproduction.https://en.wikipedia. org/wiki/ Chromosomal_ crossover
126CyanobacteriaAn ancient phylum of bacteria that performs photosynthesis to fix carbon from carbon dioxide and generate energy through photosynthesis.Oxygen is produced as a byproduct.https://en.wikipedia. org/wiki/ Cyanobacteria
127CysteineOne of the 20 amino acids found in all living things. Contains a sulfur atom in its side chain, and is often found covalently bonded to other cysteine residues, forming S−S which is called cystine.https://en.wikipedia. org/wiki/Cysteine
128CytoplasmAll of the internal material within a living cell (except the nucleus), which is surrounded by the cell membrane. In eukaryotes, the cytoplasm excludes the nucleus. In prokaryotes, the cytoplasm includes all of the internal material of the cell.https://en.wikipedia. org/wiki/Cytoplasm
129Cytoplasmic determinantMaterials such as RNA and proteins that are of maternal origin and are usually asymmetrically distributed in fertilized eggs (zygotes). Play important roles in early embryonic development.https://en.wikipedia.org/wiki/Cytoplasmic_determinant
130CytoskeletonCytoplasmic elements such as actin microfilaments, microtubules, and intermediate filaments that are involved in cellular transport, shape, and motility.https://en.wikipedia. org/wiki/ Cytoskeleton
131Dark matterA hypothetical form of matter that is thought to account for approximately 85% of the matter in the universe. Metaphorically, may also refer to as yet uncharacterized genomic elements that contribute to development.https://en.wikipedia. org/wiki/ Dark_matter
132Deep homologyCharacteristic of highly-conserved genes and structures found in distant organisms, which often play important roles in development.https://en.wikipedia. org/wiki/ Deep_homology
133DeletionA mutation in which part of a chromosome or a sequence of DNA is lost, often during DNA replication. Deletions can range in length from a single nucleotide up to large portions of an entire chromosome.https://en.wikipedia. org/wiki/ Deletion_(genetics)
134DenaturationUnfolding and/or inactivation of a macromolecule such as a protein. This can occur by extremes of temperature, pH, or presence or absence of other chemicals such as ions, desiccation, or interfaces between gaseous and aqueous phases.https://en.wikipedia. org/wiki/ Denaturation_ (biochemistry)
135DesiccationA general term that refers to removal or absence of water. Most living cells require environmental conditions that prevent desiccation, although some spores, seeds, and some specialized species have evolved so that they can remain dormant but viable following desiccation.https://en.wikipedia. org/wiki/Desiccation
136Development (embryogenesis)A term describing a broad range of processes that take place throughout all stages of the life cycle, primarily in multicellular organisms. Often refers to the process whereby biological organization is reproduced from a fertilized egg which undergoes cleavage, gastrulation, embryogenesis, and organogenesis. During this process the body plan is formed and cells cooperate to generate integrated patterns and specialized cells, tissues, and organs. Development also refers to growth that takes place after embryogenesis, differentiation of stem cells, pattern formation, metamorphosis, and more.https://en.wikipedia. org/wiki/ Embryogenesis
137Developmental biologyA broad interdisciplinary field in biology that studies animal or plant growth and development. In addition to development of embryos, it also encompasses the biology of normal growth, regeneration, asexual reproduction, metamorphosis, stem cells, and cancer.https://en.wikipedia. org/wiki/ Developmental_ biology
138Developmental toolkitA metaphorical description of modular structures, functions, and genetic determinants at various levels of complexity that contribute to development. Toolkit elements are often reused and modified in a variety of ways by natural processes, during biological evolution.
139Differentiation (cellular)Specialization of embryonic cells or stem cells during development, resulting from factors such as cytoplasmic determinants, cellular communication, epigenetic changes in specific cell lineages, and transcription factors. Examples include muscle cells, lymphocytes, and sex cells. May occur during embryonic development or during growth or regeneration in the juvenile or adult.https://en.wikipedia. org/wiki/ Cellular_ differentiation
140Digital physicsA collection of theoretical perspectives based on the premise that the universe is describable by information. It is a form of digital ontology about the physical reality. According to this theory, the universe can be conceived of as either the output of a deterministic or probabilistic computer program, a vast, digital computation device, or mathematically isomorphic to such a device.https://en.wikipedia. org/wiki/ Digital_physics
141DiploidEukaryotic cells that have two sets of homologous chromosomes, commonly found among sexually reproducing plants and animals.https://en.wikipedia. org/wiki/Ploidy
142Dipole (molecular)An asymmetrical directional charge distribution in polar molecules with a positive end and a negative end, which may exert attractive or repulsive forces on other nearby molecules. Transient dipoles can also be formed by random interactions between electron clouds of adjacent molecules.https://en.wikipedia. org/wiki/Dipole_ (disambiguation)
143Dipole−dipole attractionsAttractions between dipoles of two polar molecules, such as water. One type of intermolecular force responsible for phase changes from gas to liquid. In water and in base-pairs of nucleic acids, relatively strong dipole−dipole attractions called hydrogen bonds play important roles in all living cells.https://en.wikipedia. org/wiki/ Intermolecular_force
144Disequilibrium (chemistry)A dynamic state in which chemical reactions between reactants and products are not taking place in both directions at equal rates. This does not imply that amounts of reactants or products are unequal. Another meaning of the term refers to gradients in the distribution of particles, such as across a semi-permeable membrane. In equilibrium, the distribution of the particles is greater on one side of the membrane.https://en.wikipedia.org/wiki/Emergence
145DisorderThe absence of order or the lack of organization. Also, may refer to entropy.https://en.wikipedia. org/wiki/Disorder
146Dispersal vectorAn agent transporting seeds or other dispersal units. They can be living or nonliving parts of the environment.https://en.wikipedia. org/wiki/ Dispersal_vector
147DNAA polymer of nucleotides, each containing the sugar deoxyribose, a phosphate group, and a nitrogenous base. In the genome, DNA usually consists of two base-paired chains that coil around each other to form a double helix. Strands can be transcribed into RNA molecules and can be replicated to form two identical copies. DNA carries the genetic instructions used in the growth, development, function, and reproduction of all living organisms.https://en.wikipedia. org/wiki/DNA
148DNA polymeraseEnzyme that synthesizes complementary strands of DNA from DNA template strands. Required for DNA replication, and may also perform DNA repair functions.https://en.wikipedia. org/wiki/ DNA_polymerase
149DNA replicationThe biological process of producing two identical replicas of DNA from the original DNA molecule. With double-stranded DNA, two identical copies are produced when the strands separate and two new complementary strands are synthesized by DNA polymerase enzymes. DNA replication occurs in all living organisms and is the basis for biological inheritance.https://en.wikipedia. org/wiki/ DNA_replication
150DNA sequence variationUsually refers to heritable differences in genomic DNA. DNA sequence variation plays a critical role in Natural Selection.https://en.wikipedia. org/wiki/ Genetic_variation
151DNA sequencingThe process of determining the precise order of organic molecules within a DNA. It includes any method used to determine the order of the four bases. These are adenine, guanine, cytosine, and thymine.https://en.wikipedia. org/wiki/ DNA_sequencing
152DNA synthesisThe natural or artificial creation of DNA molecules, usually starting with a template strand.https://en.wikipedia. org/wiki/ DNA_synthesis
153DNA/RNA templatesDuring DNA replication or transcription, a single strand of DNA serves as a template for the synthesis of a complementary (base-paired) strand of DNA or RNA by DNA or RNA polymerase enzymes, respectively. During reverse transcription, a strand of RNA serves as a template for synthesis of a complementary DNA strand by reverse transcriptase.(not applicable)
154Dominance (genetics)A relationship between alleles of one gene in which the effect on phenotype of one allele masks the contribution of the second allele. The first is dominant over the second.https://en.wikipedia. org/wiki/ Dominance_ (genetics)
155Double-stranded (base-paired)Refers to DNA, RNA, or DNA/RNA hybrids in which nitrogenous bases are paired and held together by hydrogen bonding. May occur within single stranded molecules such as tRNA which fold into a cloverleaf shape, or may occur between two formerly separate strands, or may arise during DNA or RNA synthesis.https://en.wikipedia. org/wiki/Base_pair
156Downstream (DNA or RNA)Relative position in DNA, RNA, or protein molecules. In nucleic acids, usually means towards the 3 end of a strand of DNA or RNA, relative to the direction of transcription or translation. In protein chains, usually means towards the carboxyl terminus of the chain.https://en.wikipedia. org/wiki/ Downstream
157Drosophila melanogaster (fruitfly)A species of fly that has been productively used as a model organism. Extensively used in Molecular Genetics. Common name is “fruitfly”. Still used extensively in biology and medicine.https://en.wikipedia. org/wiki/ Drosophila_ melanogaster
158Escherichia coliBacterial commonly found in the lower intestine of warm-blooded organisms, including humans. Most strains are harmless, but some can cause serious food poisoning in their hosts. Commonly used as model organism and recombinant DNA technology.https://en.wikipedia. org/wiki/ Escherichia_coli
159Ecological PhenotypeTerm introduced in Rethinking Evolution referring to the fully-developed structures, functions, and organization of the individual that adapt the individual to a particular environmental niche or way of life.https://en.wikipedia. org/wiki/Phenotype
160Ecological relationshipsRelationships between organisms and abiotic (nonliving) features of shared environments. All species depend on effective ecological relationships to survive and reproduce their own kind. Relatively sudden changes in abiotic factors (such as temperature) play major roles in extinction—particularly when other species depend on a producer at the bottom of the food web, or a keystone species, that is affected by the change.https://en.wikipedia. org/wiki/Ecology
161EcosystemA community made up of living organisms and nonliving components such as air, water, minerals, and/or soil. Living and nonliving components interact through nutrient cycles and energy transformation and exchange.https://en.wikipedia. org/wiki/Ecosystem
162EctosymbioticSymbiosis in which the symbiont lives on the body surface of the host. This can be internal surfaces like digestive tubes or ducts of glands.https://en.wikipedia. org/wiki/ Ectosymbiosis
163Efficacy (wiktionary)The effectiveness of an entity in performing specific tasks.https://en.wiktionary. org/wiki/efficacy
164Egg cellThe female reproductive cell (sex cell) in sexually reproducing species. A zygote is formed when the egg is fertilized by a sperm cell, which can lead to development of an embryo.https://en.wikipedia. org/wiki/Egg_cell
165ElectronA particle smaller than an atom with a negative charge. Electrons play essential roles in both weak and strong chemical bonding, ionization, electricity, magnetism, thermal conductivity, and more.https://en.wikipedia. org/wiki/Electron
166Electron bifurcation (from published abstract).The coupling of exergonic and endergonic redox reactions to simultaneously generate (or utilize) low- and high-potential electrons. It is the third recognized form of energy conservation in biology and was recently described for select electron-transferring flavoproteins.https://jb.asm.org/ content/199/21/ e00440-17
167Electron cloudThe 3D space containing electron orbitals of a molecule or atom.https://en.wikipedia. org/wiki/ Electron-cloud_ effect
168Electron microscopeA microscope that uses a focused beam of accelerated electrons rather than light to form an image. They are used to investigate the structure or microorganisms, large molecules, cell samples, metals, and crystals.https://en.wikipedia. org/wiki/ Electron_ microscope
169Electron pairTwo electrons that occupy the same molecular orbital. Often, this may be a hybrid orbital representing a covalent bond between two atoms.https://en.wikipedia. org/wiki/ Electron_pair
170Electron transport chainA series of complexes that transfer electrons from electron donors to electron acceptors via redox (both reduction and oxidation occurring simultaneously) reactions, and couples this electron transfer with the transfer of protonshttps://en.wikipedia. org/wiki/ Electron_transport_ chain
171Embryo (multicellular eukaryote)An embryo is an early stage of development of a multicellular diploid eukaryotic organism. In general, in organisms that reproduce sexually, an embryo develops from a zygote, the single cell resulting from the fertilization of the female egg cell by the male sperm cell. The zygote possesses half the DNA from each of its two parents. In plants, animals, and some protists, the zygote will begin to divide by mitosis to produce a multicellular organism. The result of this process is an embryo.https://en.wikipedia. org/wiki/Embryo
172Embryonic development (embryogenesis)Embryogenesis is the process by which the embryo forms and develops. In mammals, the term refers chiefly to early stages of prenatal development, whereas the terms fetus and fetal development describe later stages. Embryogenesis starts with the fertilization of the egg cell (ovum) by a sperm cell, (spermatozoon). Once fertilized, the ovum is referred to as a zygote, a single diploid cell. The zygote undergoes mitotic divisions with no significant growth (a process known as cleavage) and cellular differentiation, leading to development of a multicellular embryo.https://en.wikipedia. org/wiki/ Embryogenesis
173Emergence (properties and processes)Resulting from a process whereby larger entities arise through interactions among smaller or simpler entities such that the larger entities exhibit properties the smaller/simpler entities do not exhibit.https://en.wikipedia.org/wiki/Emergence
174Emergent Evolutionary Potential (EEP)Term introduced in Rethinking Evolution. Refers to the changing potential for higher-level organization to arise when new entities interact in ways that prove useful in survival and reproduction.(not applicable)
175Emergentism (system)A property of a system is said to be emergent if it is a new outcome of some other properties of the system and their interaction, while it is itself different from them.https://en.wikipedia. org/wiki/ Emergentism
176Empirical dataData gathered from the real world through observations and experiments. The scientific method demands that such data should be based on true objective facts that are reproducible, and that are precisely described in an unambiguous way.https://en.wikipedia. org/wiki/ Empirical_evidence
177Empirical evidenceEvidence gathered from the real world through observations and experiments. The scientific method demands that such data should be based on true objective facts that are reproducible, and that are precisely described in an unambiguous way. Empirical evidence is used to test the validity of hypotheses, claims and ideas about the real world.https://en.wikipedia. org/wiki/ Empirical_evidence
178Empirical researchResearch using observable and documented evidence. This is accomplished through direct or indirect observation or experience.https://en.wikipedia. org/wiki/ Empirical_research
179Endergonic reactionA chemical reaction that absorbs energy from the surroundings. Since the energy is gained, the energy change has a positive sign.https://en.wikipedia. org/wiki/ Endergonic_reaction
180EndosymbiosisA well-supported theory for the origin of eukaryotic cells from prokaryotic organisms. Organelles such as mitochondria and chloroplasts evolved from bacteria that were engulfed by other cells.https://en.wikipedia. org/wiki/ Symbiogenesis
181EnergyA quantifiable property of matter. Energy can often be harnessed to do work. Energy can be converted into other forms, but cannot be created no destroyed.https://en.wikipedia.org/wiki/Energy
182Energy dissipationThe natural spontaneous tendency of energy to become distributed. Energy spontaneously moves from regions or objects of higher energy to regions of lower energy if there is nothing blocking that movement. Energy dissipation takes place over time, and is affected by the nature of the materials involved. This is an area of study in thermodynamics.https://en.wikipedia. org/wiki/Dissipation
183EntityA general term for any type of discrete identifiable object, unit or subunit, whether simple or complex.https://en.wikipedia. org/wiki/Entity
184Entropy(thermodynamics)An extensive property of a thermodynamic system. Representing the amount of disorder in a system, entropy can be measured by determining the number of microstates of particles, temperature, or energy of a system.https://en.wikipedia. org/wiki/Entropy
185Enzymatic activityBinding of reactants (substrates) to the active site of enzymes, followed by catalytic facilitation of the chemical reaction and release of the products.https://en.wikipedia. org/wiki/Enzyme
186EnzymeMacromolecular biological catalysts. Most enzymes are proteins, but some RNA sequences also have catalytic activity. Enzymes facilitate chemical reactions by binding to specific reactant molecules and lowering the activation energy required for chemical reactions. Each step in a metabolic pathway is usually carried out by a specific enzyme, and enzymes may also change the activity of other molecules by modifying them in various ways. For example, protein kinases are enzymes that regulate many cellular processes by adding phosphate groups to protein chains.https://en.wikipedia. org/wiki/Enzyme
187EpigeneticAn added genetic affect that is determined by factors other than the DNA sequence per se. May involve chemical modifications of the DNA, condensation of chromosomes, and other factors.https://en.wikipedia. org/wiki/Epigenetics
188EpistasisThe phenomenon where the effect of one gene is dependent on other genes in the genome.https://en.wikipedia. org/wiki/Epistasis
189EpistemologyThe branch of philosophy concerned with the theory of knowledge. It involves studying the nature of knowledge, justification, and the rationality of belief.https://en.wikipedia. org/wiki/ Epistemology
190Equilibrium (chemical)A dynamic state in which chemical reactions between reactants and products are taking place in both directions at equal rates. This does not imply that amounts of reactants or products are equal. Another meaning of the term refers to gradients in the distribution of particles, such as across a semi-permeable membrane. At equilibrium, the distribution of the particles is equal on both sides of the membrane.https://en.wikipedia. org/wiki/ Chemical_ equilibrium
191Eubacteria (bacteria)Single-celled organisms from one of the two domains of prokaryotes. The other domain is archaea.https://en.wikipedia. org/wiki/Bacteria
192EuglenidOne of the best-known groups of flagellates, commonly found in freshwater, especially when it is rich in organic materials. Most euglenids are unicellular. Many euglenids have chloroplasts and produce their own food through photosynthesis, but others feed by phagocytosis, or strictly by diffusion.https://en.wikipedia. org/wiki/Euglenid
193EukaryoticCells or individuals that are classified in the domain of organisms designated Eukaryota. Eukaryotic cells have a nucleus enclosed within membranes as well as membrane-bound organelles. Distinguished from prokaryotic cells.https://en.wikipedia. org/wiki/Eukaryote
194Evo-devo (evolutionary developmental biology)Abbreviation for evolutionary developmental biology. A field of biological research that compares the developmental processes of organisms. This allows inference of ancestral relationships and evolutionary origins of developmental processes.https://en.wikipedia. org/wiki/ Evolutionary_ developmental_ biology
195Evo-psych (evolutionary psychology)Abbreviation for evolutionary psychology. A theoretical approach that draws on both social and natural sciences. Psychological structure is examined from a modern evolutionary perspective. Usually requires interdisciplinary knowledge in evolutionary biology, psychology, and social sciences.https://en.wikipedia. org/wiki/ Evolutionary_ psychology
196Evolution (biology)The empirically proven natural process of change in all living things on Earth. Natural Selection is one of the most fundamental mechanisms that account for biological evolution, but it is not the only relevant mechanism involved. Biological evolution includes the precellular molecular changes that led to the origin of life on Earth, as well as subsequent changes in the complexity of structures and functions in all living cells and organisms. Evolution is also the fundamental process responsible for the Origin of Species, as pointed out by Charles Darwin in 1859, in the context of Natural Selection.https://en.wikipedia. org/wiki/Evolution
197Evolutionary conservationConservation (preservation and hereditary transmission) of genetic determinants in the genome, as well as the higher-level developmental processes and developed structures and functions that arise from such conserved genetic elements. For example, conservation of the widespread uniformity of transcription and translation as well as ATP synthases that convert the energy of proton gradients are conserved elements that require conservation of the DNA sequences that determine the amino acid sequences of the proteins involved. Similarly, deep conservation of the body plans of vertebrates depends on conservation of genetic elements such as Hox genes.https://en.wikipedia. org/wiki/ Conserved_sequence
198Evolutionary developmental biology(evo-devo)A field of biological research that compares the developmental processes of organisms. This allows inference of ancestral relationships and evolutionary origins of developmental processes.https://en.wikipedia. org/wiki/ Evolutionary_ developmental_ biology
199Evolutionary psychology (evo-psych)A theoretical approach that draws on both social and natural sciences. Psychological structure is examined from a modern evolutionary perspective. Usually requires interdisciplinary knowledge in evolutionary biology, psychology, and social sciences.https://en.wikipedia. org/wiki/ Evolutionary_ psychology
200EvolvabilityThe capacity of a system for adaptive evolution. It is the ability of a population of organisms to generate adaptive genetic diversity.https://en.wikipedia. org/wiki/ Evolvability
201ExaptationThe natural reuse, with or without modification, of genetic determinants for new purposes, in biological evolution.https://en.wikipedia. org/wiki/Exaptation
202ExergonicA chemical reaction that loses energy to the surroundings. Since the energy is lost, the energy change has a negative sign.https://en.wikipedia. org/wiki/ Exergonic_reaction
203ExonThe protein-coding portions of eukaryotic genes that are spliced together during processing of RNA to generate messenger RNA sequences.https://en.wikipedia. org/wiki/Exon
204Expanded evolutionary synthesisAlthough there is debate among evolutionary biologists, the term is generally used to describe an evolutionary synthesis that retains certain core principles of classical Darwinism and the Modern Synthesis while expanding and modifying it with newly acquired concepts that are well-supported by empirical evidence.http://courses. washington.edu/ biol354/niklas.pdf
205Experimental embryologyExperiments primarily involving disaggregation and reaggregation of cells, transplantation of cells, or mixing of cells, that provided phenomenological insights into the mechanisms of development. This was an active area of investigation in the 20th century in several countries throughout the world.(not applicable)
206Extended evolutionary synthesisA set of theoretical concepts more comprehensive than the earlier modern synthesis of evolutionary biology that took place between 1918 and 1942. The extended evolutionary synthesis was called for in the 1950s by C. H. Waddington, argued for on the basis of punctuated equilibrium by Stephen Jay Gould and Niles Eldredge in the 1980s, and was reconceptualized in 2007 by Massimo Pigliucci and Gerd B. Müller.https://en.wikipedia. org/wiki/ Extended_ evolutionary_ synthesis
207ExtinctionThe termination of evolutionary lineages, including one or more species, during the evolutionary process. Most of the species that have ever lived on planet Earth have gone extinct, and only a small fraction continues to live (these are extant species). Extinction occurs when populations of a species no longer leave descendant offspring, and when the last living individual dies.https://en.wikipedia. org/wiki/Extinction
208Extracellular matrixMacromolecular structures that surround cells, outside of the cell membrane, consisting of a variety of complex molecules such as interacting carbohydrates and proteins. The extracellular matrix is involved in a broad range of functions both during development and also in mature tissues and organs.https://en.wikipedia. org/wiki/ Extracellular_matrix
209ExtremophileAn organism or species that thrives under conditions that are usually lethal to most other species, such as extremes of temperature, ionizing radiation, salinity, desiccation, and other extreme environmental conditions.https://en.wikipedia. org/wiki/ Extremophile
210Eyespot (mimicry)A pigmented structure, for example on a butterfly wing or a caterpillar, that resembles an eye but does not actually function at all in vision. Eyespots presumably evolve because they fool would-be predators, because they play roles in mate preferences in sexual selection, or because in general they make an individual look larger or more threatening to other individuals.https://en.wikipedia. org/wiki/ Eyespot_(mimicry)
211FacilitateTo help bring about or to make easier.https://en.wiktionary. org/wiki/facilitate
212Facilitated variationDemonstrates how seemingly complex biological systems can arise through a limited number of regulatory genetic changes. This occurs through differential re-use of preexisting developmental components.https://en.wikipedia. org/wiki/ Facilitated_variation
213Fate map (fate mapping)A mapping of embryonic cells that demonstrates how particular cells will ultimately migrate, differentiate, specialize, and form specific mature tissues and organs.https://en.wikipedia. org/wiki/ Fate_mapping
214Fatty acidA carboxyl functional group covalently bonded to a long hydrocarbon chain. Found as components of biological membranes and function as stored energy sources.https://en.wikipedia. org/wiki/Fatty_acid
215FertilizationIn sexual reproduction, the fusion of a sperm cell and an egg cell to form a zygote or fertilized egg, which may then go on to undergo subsequent cleavage, gastrulation, and embryonic development. Usually, one set of maternal genes and one set of paternal genes are combined to form a diploid genome with two sets of chromosomes.https://en.wikipedia. org/wiki/ Fertilisation
216Fertilized egg (zygote)An egg that has combined with the genome of a sperm cell, the prerequisite to embryonic development.https://en.wikipedia. org/wiki/Zygote
217FlagellumA lash-like appendage that protrudes from the cell body of certain bacterial and eukaryotic cells and whose primary function is locomotion, but it also often has function as a sensory organelle, being sensitive to chemicals and temperatures outside the cell. The similar structure in the archaea functions in the same way but is structurally different.https://en.wikipedia. org/wiki/Flagellum
218FlavinsA group of organic compounds based on pteridine, a chemical compound. Flavins are capable of undergoing redox reactions.https://en.wikipedia. org/wiki/ Flavin_group
219Flow cytometryA technique in which individual cells are sorted into separate groups, usually by means of cell-surface proteins that have been attached to fluorescent antibodies. Flow cytometry may be performed for analytical and/or preparative purposes.https://en.wikipedia. org/wiki/ Flow_cytometry
220Food webA natural interconnection of food chains, in which organisms consume other organisms to obtain energy and nutrients. A major feature of ecosystems.https://en.wikipedia. org/wiki/Food_web
221Frameshift mutationA genetic mutation caused by insertion or deletion of nucleotides in a protein-coding DNA sequence. This can alter downstream codons and result in changes in the amino acid sequence and/or length of a protein chain.https://en.wikipedia. org/wiki/ Frameshift_mutation
222Fruitfly (Drosophila melanogaster)A fly of the species Drosophila melanogaster that has played crucial roles in Mendelian Genetics, Molecular Genetics, evolutionary biology, and evo-devo as a model organism.https://en.wikipedia. org/wiki/ Drosophila_ melanogaster
223Functional groupA chemical group that is usually attached to one or more carbon atoms in organic compounds. Examples include amino groups and carboxyl groups found in all amino acids.https://en.wikipedia. org/wiki/ Functional_group
224Fungus (fungal)Any member of the group of eukaryotic organisms in the Fungi kingdom, such as yeasts, molds, and mushrooms. Fungi are usually decomposers in ecological systems.https://en.wikipedia. org/wiki/Fungus
225G protein-coupled receptorG-proteins in the cytoplasm, that play various roles in signal transduction pathways. Examples include photoreceptors involved in vision and olfactory receptors involved in the sense of smell (odor detection).https://en.wikipedia. org/ wiki/G_protein-coupled_receptor
226Gap geneA type of gene involved in the development of the segmented embryos of some arthropods. Gap genes are defined by the effect of a mutation in that gene, which causes the loss of contiguous body segments, resembling a gap in the normal body plan. Each gap gene, therefore, is necessary for the development of a section of the organism. In situ hybridization against mRNA for some of the gap genes in the Drosophila early embryo. Gap genes were first described by Christiane Nüsslein-Volhard and Eric Wieschaus in 1980.https://en.wikipedia. org/wiki/Gap_gene
227GastrulationA widespread developmental process in a variety of animals that establishes cell layers in the embryo by means of cellular motility and migration In general terms, cells change shape and turn inward to form new layers beneath other cells. Essential to the establishment of the overall shape and form of the body, and to organ development.https://en.wikipedia. org/wiki/ Gastrulation
228GeneA sequence of DNA or RNA that “codes” for a gene product such as a protein, or exerts a regulatory effect on gene expression. Most biological traits are determined by the effects of multiple interacting genes and gene products.https://en.wikipedia. org/wiki/Gene
229Gene duplicationA major mechanism through which new genetic material is generated during molecular evolution. It involves duplication of a region of DNA that contains one or more genes.https://en.wikipedia. org/wiki/ Gene_duplication
230Gene expressionThe regulated process by which genes produce their gene product or products, such as protein chains or various types of functional RNA sequences. Usually begins with control of transcription.https://en.wikipedia. org/wiki/ Gene_expression
231Gene poolA set of genes in a population of individual organisms. A gene pool implies relatively free flow of genetic material between individuals, usually referring to sexual reproduction within a single eukaryotic species, but also possibly by horizontal gene transfer, for example between prokaryotes.https://en.wikipedia. org/wiki/Gene_pool
232Gene productThe biochemical material resulting from expression of a gene. Usually, genes are expressed as protein chains or as RNA molecules.https://en.wikipedia. org/wiki/ Gene_product
233Generalist (natural sciences)A researcher or theorist with interdisciplinary interests. Often, generalists try to understand the metaphorical “Big Picture” that represents a broad understanding of reality. In the biological sciences and biomedical research, most funded research is carried out by specialists rather than generalists.https://en.wikipedia. org/wiki/Generalist
234Generative PhenotypeA term introduced in Rethinking Evolution to help clarify the difference between developmental toolkit elements and the overall phenotype of the developed individual. Refers to the shape and form and capabilities of structures and functions at various levels of complexity that function as reusable modules in development. These modular elements play major roles during the development of organisms, and are themselves subject to both evolutionary conservation and evolutionary modification and refinement. Distinguished from the Ecological Phenotype.(not applicable)
235Genetic algorithmA software technique inspired by Natural Selection, in which strings of computer code are recombined in a random fashion and then subjected to artificial selection according to some predetermined criteria. Selected strings are replicated, artificially varied, and then subjected to subsequent recombination and selection. A powerful technique for solving multivariate problems in which the best ways to achieve the desired ends are difficult for the human mind to conceive.https://en.wikipedia. org/wiki/ Genetic_algorithm
236Genetic apparatus (genetics, gene expression)Modular structures and functions including chromosomes (the full genome), transcription factors, enzymes, and proteins involved in transcription, translation, mitosis, and meiosis, and various RNA molecules, which all work together to store, transmit, diversify, shuffle, and express genetic determinants to reproduce biological structures and functions via the development of each individual.https://en.wikipedia.org/wiki/Genetics
237Genetic blueprint (metaphorical)A misleading metaphor that arose from a teleological view of the ways that genes and their regulated expression determine biological structure and function.https://en.wikipedia.org/wiki/Blueprint
238Genetic codeA table that links specific triplets (codons) in DNA or RNA to specific amino acids (or start or stop signals). These amino acids are incorporated into a growing protein chain during protein synthesis.https://en.wikipedia. org/wiki/ Genetic_code
239Genetic determinantsTranscribed and translated RNA molecules and protein chains, as well as a variety of regulatory DNA sequences that interact in complex ways to generate and reproduce the phenotypes characteristic of individuals and species.https://en.wikipedia. org/wiki/Genetics
240Genetic materialDNA is the universal genetic material of all types of cells. It is located in the chromosomes of prokaryotic and eukaryotic cells, as well as in the smaller genomic elements of organelles such as mitochondria and chloroplasts.https://en.wikipedia. org/wiki/Genetics
241Genetic transformationThe genetic alteration of a cell resulting from direct uptake and incorporation of DNA originating outside the organism. This occurs from its surroundings through the cell membranes. It can occur naturally or can be facilitated by specialized techniques in biotechnology.https://en.wikipedia. org/wiki/ Transformation_ (genetics)
242Genetic variationA general term for heritable variation which can be traced to specific sequences of genomic DNA.https://en.wikipedia. org/wiki/ Genetic_variation
243GeneticsThe study of the nature, storage, transmission, and expression of the heritable factors found in genomic DNA. Some of the major interdisciplinary fields in genetics are Mendelian Genetics, Molecular, Genetics, and Developmental Genetics.https://en.wikipedia. org/wiki/Genetics
244GenomeThe complete set of genetic material of an organism of a given species. May refer to an individual genome or the collective gene pool of the species as a whole. It consists of DNA.https://en.wikipedia. org/wiki/Genome
245Genome evolutionAccumulated changes in the genetic material of various populations and species over time, resulting from changes in the frequencies of various genetic determinants.https://en.wikipedia. org/wiki/ Genome_evolution
246Genomic DNAThe complete set of DNA sequences contained in the cells of, and passed from generation to generation, during the reproduction of a species of organism.https://en.wikipedia. org/wiki/ Genomic_DNA
247Genomic toolkitA metaphorical description of modular, reusable genomic elements, and processes such as gene duplication and conserved regulatory or protein-coding sequences. Toolkit elements play major roles in development and general cellular functions and are often modified and reused in various ways by Natural Selection.(not applicable)
248GenotypeThe specific alleles usually represented by the DNA sequences of one or two copies of a specific gene in an individual, which contributes to the genetic makeup of a cell, and may contribute to the phenotype.https://en.wikipedia. org/wiki/Genotype
249GeologyAn earth science concerned with the solid Earth made of rock and the processes by which it changes over time.https://en.wikipedia. org/wiki/Geology
250Germ layersThe layers of developing embryonic cells that interact to form tissues and organs. The three major germ layers are ectoderm, mesoderm, and endoderm.https://en.wikipedia. org/wiki/ Germ_layer
251Germ line (cells or DNA)Usually refers to diploid cells that produce haploid sex cells during sexual reproduction. Germ line DNA may refer to the genome of immature lymphocytes that have not undergone V(D)J recombination.https://en.wikipedia. org/wiki/Germline
252Gestalt (biology)A general term for overall, interconnected wholes that have modules that interact to generate higher levels of emergent structure and function.https://en.wikipedia. org/wiki/Gestalt
253Gradient (chemical or morphogenetic)An unequal distribution or concentration of a substance, which may or may not be separated by a semi-permeable membrane. Gradients can consist of ions, small molecules, or DNA or RNA.(not applicable)
254Green algaeA large, informal grouping of algae. The land plants, or embryophytes, are thought to have emerged from the charophytes.https://en.wikipedia. org/wiki/ Green_algae
255Group selectionA proposed mechanism of evolution in which Natural Selection acts at the level of the group, instead of at the more conventional level of the individual.https://en.wikipedia. org/wiki/ Group_selection
256H^+Hydrogen ions, which are positively charged protons from hydrogen atoms that have been ionized and lost their electrons. Hydrogen ions play important roles in biological proton gradients and their concentration determines the acidity or alkalinity (pH) of aqueous solutions.https://en.wikipedia. org/wiki/ Hydrogen_ion
257HeatEnergy transferred from one system to another as a result of thermal interactions.https://en.wikipedia. org/wiki/Heat
258Hedgehog (signaling pathway)A signaling pathway that transmits information to embryonic cells required for proper cell differentiation. Different parts of the embryo have different concentrations of hedgehog signaling proteins. The pathway also has roles in the adult. Diseases associated with the malfunction of this pathway include basal cell carcinoma.https://en.wikipedia. org/wiki/ Hedgehog_ signaling_pathway
259Hereditary factorA genetic determinant. Includes DNA sequences that are transcribed and translated into RNA molecules and amino acid sequences, as well as DNA sequences involved in control of gene expression.https://en.wikipedia. org/wiki/Heredity
260Heredity (genetics)The nature, storage, transmission, and expression of genetic determinants that are passed from generation to generation in all species.https://en.wikipedia. org/wiki/Heredity
261HeterogeneousRefers to a mixture containing components that are diverse and/or unevenly distributed.https://en.wikipedia. org/wiki/ Homogeneity_and_ heterogeneity
262HeterotrophAn organism that must consume (internalize) and metabolize organic compounds from other organisms to obtain energy and nutrients for synthesizing macromolecules.https://en.wikipedia. org/wiki/ Heterotroph
263HeterozygousIf two alleles of a gene carried on homologous chromosomes of a diploid organism are distinct, the organism is heterozygous at that genetic locus.https://en.wikipedia. org/wiki/Zygosity
264high-energy compounds (biology)In biology, usually refers to molecules such as ATP (as well as other nucleotide triphosphates), NADH, NADPH, and FADH2. Energy is usually released by enzymes that break unstable bonds that are the source of energy in these compounds. They are widely used sources of energy that drive cellular, metabolic processes requiring an external energy source, including photosynthesis, cellular respiration, and in general anabolic reactions that build up larger molecules from smaller ones.https://en.wikipedia. org/wiki/High-energy_ phosphate
265HolonSomething that is part of a whole but with some degree of autonomy. They have a degree of autonomy but are subject to control from higher authorities.https://en.wikipedia. org/wiki/ Holon_(philosophy)
266Homeodomain (homeobox)A DNA sequence, around 180 base pairs long, found within genes that are involved in the regulation of patterns of anatomical development (morphogenesis) in animals, fungi and plants. These genes encode homeodomain protein products that are transcription factors sharing a characteristic protein fold structure that binds DNA.https://en.wikipedia. org/wiki/Homeobox
267Homologous pairA set of one maternal and one paternal chromosome that pair up with each other inside a cell during meiosis.https://en.wikipedia. org/wiki/ Homologous_ chromosome
268Homology (biology)A characteristic of conserved sequences in DNA (or RNA or protein) sequences, or phenotypic structures and functions determined by genetic elements, that are derived from common ancestral genes or organisms. Homologous DNA sequences are found either by sequence comparisons or by experimental methods in which similar single-stranded sequences from two genes or two organisms will base-pair (hybridize) to form double-stranded hybrid sequences.https://en.wikipedia. org/wiki/ Homology_ (biology)
269HomozygousIf both alleles of a gene carried on homologous chromosomes of a diploid organism are the same, the organism is homozygous at that genetic locus.https://en.wikipedia. org/wiki/Zygosity
270Horizontal gene transfer (lateral gene transfer)The movement of genetic material between organisms other than by the transmission of DNA from parent to offspring. It is an important factor in the evolution of many organisms.https://en.wikipedia. org/wiki/ Horizontal_gene_ transfer
271Hox geneA group of related genes that control the body plan of a broad range of animal embryos along the head-tail axis. A subset of the homeotic gene family.
https://en.wikipedia. org/wiki/Hox_gene
272Hybrid orbital (chemistry)An orbital occupied by a pair of electrons that extends between two atoms in a covalent bond. Hybrid orbitals have different shapes than orbitals of isolated atoms and bind atoms together by a strong electromagnetic force that often requires a chemical reaction to separate the bonded atoms.https://en.wikipedia. org/wiki/ Orbital_ hybridisation
273Hybridization (nucleic acid)Formation of a double-stranded hybrid sequence from DNA and RNA strands, or from two different genes or organisms.https://en.wikipedia. org/wiki/ Hybridisation
274Hydrogen atom (H)An atom of the simplest chemical element, which in neutral form contains one proton and one electron. Hydrogen atoms constitute about 75% of the baryonic mass of the universe.https://en.wikipedia. org/wiki/ Hydrogen_atom
275Hydrogen bondingA partially electrostatic attraction between molecules, where two relatively strong dipoles formed by hydrogen and oxygen, hydrogen and nitrogen, or hydrogen and fluorine interact. Hydrogen bonding plays critical roles in base-pairing of nucleotides and in the structure of macromolecules.https://en.wikipedia. org/wiki/ Hydrogen_bond
276Hydroxide ion (OH^-)An oxygen atom covalently bonded to a hydrogen atom which has gained an extra electron with its negative charge. Contributes to alkalinity in aqueous solutions.https://en.wikipedia.org/wiki/Hydroxide
277HypothesisA general feature of scientific inquiry and research and the scientific method. Hypotheses should be precisely stated and testable by experiments, observations, and principles that are objective and reproducible.https://en.wikipedia. org/wiki/Hypothesis
278Immune systemA host defense system comprising many biological structures and processes within an organism. Protects an organism from diseases and threats caused by pathogens, toxins, and/or cancer cells. Immune systems may include both innate and adaptive components (see adaptive immune system).https://en.wikipedia. org/wiki/ Immune_system
279Immunoglobulin superfamilyA large and diverse gene family (and its protein products) that includes large subfamilies of segments of T-cell receptor and antibody proteins, as well as other cell-surface antigens and functional proteins found on body cells (such as the major histocompatibility complex) and cells of the innate and adaptive immune systems (such as CD4 and CD8 cells that distinguish functional subsets of T cells). The immunoglobulin superfamily is named after classes of antibodies called immunoglobulins. The superfamily is involved in complex molecular, cellular, and developmental interactions and communications, especially involving the adaptive immune system.https://en.wikipedia. org/wiki/ Immunoglobulin_ superfamily
280ImpermeableA barrier that does not let other substances or objects pass through.https://en.wikipedia. org/wiki/ Permeability_ (earth_sciences)
281Implicit information contentA concept in developmental and Molecular Genetics advanced by Gunther Stent that recognizes the importance of higher-level emergent properties and interactions—and not just explicit DNA sequences—of genomic DNA, in the reproduction of species-specific biological organization in each generation.https://en.wikipedia. org/wiki/Implicit
282In situ hybridizationA powerful laboratory technique involving nucleic acid hybridization of fluorescent or otherwise tagged probes. This technique is used to render patterns of gene expression visible within intact biological specimens, such as the embryos of fruitflies. A similar technique, using fluorescent antibodies, can be used to render specific proteins visible.https://en.wikipedia. org/wiki/In_ situ_hybridization
283Incomplete dominanceA genetic relationship between alleles in which expression of both alleles in a heterozygous individual determines intermediate phenotypes. For example, red and white alleles that together generate pink flower color represent incomplete dominance.https://en.wikipedia. org/wiki/ Dominance_ (genetics)
284Induced fitShape change in the active site of an enzyme when it binds to reactants that improves the snugness of the fit between the active site and the reactants.https://en.wikipedia.org/wiki/Enzyme_catalysis
285Infinitesimal variations (Natural Selection)Refers to the slight variations that Darwin hypothesized are subjected to selection. When the variations are useful in the context of the struggle for existence, they tend to accumulate and lead to larger changes.https://en.wikipedia. org/wiki/ Infinitesimal
286Information (genetic)Refers to the determinants transmitted from generation to generation in the DNA sequences of the genome. Since many types of explicit and implicit information can be found in the genome, this term tends to be an oversimplification when used to describe the relationship between genotype and phenotype.https://en.wikipedia. org/wiki/Genome
287Information content (biology)In biology, attempts to describe DNA sequences in reductionist terms of probability or Shannon entropy. This approach fails to recognize the implicit information and emergent properties of complex molecular, cellular, and developmental interactions.https://en.wikipedia. org/wiki/ Entropy_ (information_ theory)
288Innate immune systemOne of the two main immunity strategies found in vertebrates (the other being the adaptive immune system). The innate immune system is an older evolutionary defense strategy, relatively speaking, and it is the dominant immune system response found in plants, fungi, insects, and primitive multicellular organisms.https://en.wikipedia. org/wiki/Innate_ immune_system
289Inner-workings of cellsA general term describing all of the complex interactions between molecular structures and functions at various levels of complexity.https://en.wikipedia. org/wiki/Cell_ (biology)
290Innovation (evolutionary biology)In the context of Rethinking Evolution, this term is frequently used to denote the evolution of useful new structures and functions at various levels of complexity, by natural processes. Does not imply conscious or supernatural design or intelligence of any kind.https://en.wikipedia. org/wiki/ Key_innovation
291InorganicSubstances that do not contain carbon atoms (excluding allotropes of carbon and small molecules such as carbon dioxide).https://en.wikipedia. org/wiki/ Inorganic_ compound
292Insertion (DNA)The addition of one or more nucleotide bases (or base-pairs) into a DNA sequence.https://en.wikipedia. org/wiki/ Insertion_(genetics)
293Integral membrane proteinA protein partially or completely embedded in the lipid bilayer of the cell membrane. Includes transmembrane cell-surface receptors, channels, active pumps, and other functional proteins. Signal sequences on portions of the protein chains lead to transport and integration of integral membrane proteins. This involves some degree of self-assembly that is determined by the chemical and physical properties of both lipids and the amino acid side-chains of the proteins.https://en.wikipedia. org/wiki/ Integral_membrane_ protein
294Integrated evolutionary synthesisAlthough there is debate among evolutionary biologists, the term is generally used to describe an evolutionary synthesis that retains certain core principles of classical Darwinism and the Modern Synthesis while expanding and modifying it with newly acquired concepts that are well-supported by empirical evidence.http://jeb.biologists. org/content/ jexbio/218/1/7.full. pdf
295Intelligent designA religious argument for the existence of God. Masquerades as an evidence-based scientific theory about life’s origins, but has been discredited as pseudoscience.https://en.wikipedia. org/wiki/ Intelligent_design
296Intermediate products (biosynthetic pathways)Products from earlier steps that serve as reactants in later steps of biosynthetic pathways.(not applicable)
297Intermolecular binding forcesWeak interactions such as dipole–dipole attractions and transient dipoles that play major roles in phase transitions in chemistry as well as biological processes such as base-pairing and protein-folding.https://en.wikipedia. org/wiki/ Intermolecular_force
298IntronSegments of eukaryotic genes that are transcribed but that are spliced out during processing of messenger RNA.https://en.wikipedia. org/wiki/Intron
299IonAn atom or molecule that has a nonzero net electrical charge. Ions can be negatively or positively charged.https://en.wikipedia. org/wiki/Ion
300Ionic compoundA chemical compound composed of ions held together by ionic bonding.https://en.wikipedia. org/wiki/ Ionic_compound
301IonizationThe process whereby an atom or a molecule acquires a negative or positive charge. This occurs when electrons are gained or lost.https://en.wikipedia. org/wiki/Ionization
302Ionizing radiationHigh-energy radiation (alpha, beta, or gamma) capable of breaking molecules such as DNA.https://en.wikipedia. org/wiki/ Ionizing_radiation
303Irreducible complexityA pseudoscientific argument that holds that certain complex biological systems cannot evolve by Natural Selection. Irreducible Complexity assumes that evolution by Natural Selection always involves accumulation of infinitesimal variations, which represents only one aspect of 21st century evolutionary theory. Irreducible complexity is central to the creationist concept of Intelligent Design, but has been rejected by the scientific community.https://en.wikipedia. org/wiki/ Irreducible_ complexity
304Junk DNA (noncoding DNA)A persistent but misleading 20th century term popularized by Susumu Ohno that refers to what are now more correctly referred to as noncoding DNA sequences. This, too is misleading, because many noncoding sequences have important functions, such as regulation of gene expression.https://en.wikipedia.org/wiki/Non-coding_DNA
305Lateral gene transfer (horizontal gene transfer)The movement of genetic material between organisms other than by the transmission of DNA from parent to offspring. It is an important factor in the evolution of many organisms.https://en.wikipedia. org/wiki/ Horizontal_gene_ transfer
306LichenA composite organism that arises from algae or bacteria living among multiple fungi in a symbiotic relationship.https://en.wikipedia. org/wiki/Lichen
307Life-history strategy (life-history theory)The ways that patterns of development, behavior, and other adaptations contribute to the long-term survival of a species. Often, life-history strategies involve major changes that adapt individuals to more than one ecological niche or way of life, such as metamorphosis of caterpillars to butterflies. Also includes reproductive strategies that may favor large numbers of offspring or fewer numbers with greater parental care.https://en.wikipedia. org/wiki/ Life_history_theory
308LigaseAn enzyme that can catalyze the joining of two molecules by forming a new covalent chemical bond.https://en.wikipedia. org/wiki/Ligase
309Linkage groupRefers to genetic maps of groups of genes known to be located on a particular homologous pair of autosomes or on a specific sex chromosome. For example, genes on human chromosome 21 are members of a linkage group.https://en.wikipedia. org/wiki/ Genetic_linkage
310LipidMacromolecule that is soluble in nonpolar solvents. They can store energy, act as signals or represent structural components of cell membranes.https://en.wikipedia. org/wiki/Lipid
311Lipid bilayerA thin polar membrane made of two layers of lipid molecules. Found in cell membranes and internal membranes of all living cells.https://en.wikipedia. org/wiki/ Lipid_bilayer
312LiterA derived unit of volume in the metric system defined by 1,000 cubic centimeters. Equivalent to 1.06 US quarts.https://en.wikipedia. org/wiki/Litre
313Lock and key (model)A metaphor for the specific 3D fit of reactants at the active sites of enzymes. The reality is that induced fits as well as shapes, plus chemical and physical properties, are involved in the binding process. Induced fit involves changes in the shape of the enzyme active site initiated by the binding process, leading to tighter and closer binding.https://en.wikipedia.org/wiki/Randomness
314Lone pair (electrons)A pair of nonbonded valence electrons of one of the atoms of a molecule. Lone pairs tend to have larger electron clouds and cause VSEPR effects (valence shell electron pair repulsion) which can cause molecular asymmetry.https://en.wikipedia. org/wiki/Lone_pair
315Lost city hydrothermal fieldThe first alkaline deep-sea hydrothermal vent, known as the Lost City, was discovered on the mid-Atlantic sea floor in 2,000. Distinguished from high-temperature hydrothermal vents known as black smokers, alkaline vents are formed by serpentinization, in which olivine (magnesium iron silicate) and similar rock on the seafloor reacts with water. This produces large volumes of hydrogen. Precipitation reactions between the warm (45–90 degrees Celsius) alkaline (pH 9–11) vent fluids and the colder, more acidic seawater create tall, porous calcium carbonate chimneys containing embedded metals and minerals. It is thought that proton gradients generated by similar, ancient vents provided the energy required for the metabolic reactions that led to the origin of life. Currently, the Lost City provides a unique protected environment supplying both energy and nutrients to thriving miniature local ecosystems of organisms.https://en.wikipedia. org/wiki/Lost_ City_Hydrothermal_ Field
316LymphocyteA white blood cell that develops into a T cell or B cell—part of the adaptive immune system.https://en.wikipedia. org/wiki/ Lymphocyte
317MacroevolutionRefers to large, visible adaptations that accumulate over evolutionary time and distinguish organisms. For example, the evolution of limbs of tetrapods is an example of macroevolution. The distinction between macroevolution and microevolution is an artificial distinction, because both are part of a natural continuum of change involving both genotypes and phenotypes.https://en.wikipedia. org/wiki/ Macroevolution
318MacromoleculeA very large molecule commonly created by the polymerization of smaller subunits. They are typically composed of thousands of atoms or more. Classes of macromolecules found in all living cells include carbohydrates, lipids, nucleic acids, and proteins.https://en.wikipedia. org/wiki/ Macromolecule
319Macroscopic realmThe realm in which relativistic or classical physics, rather than quantum mechanics, can predict the behavior and outcomes of events and interactions.https://en.wikipedia. org/wiki/ Quantum_realm
320Maternal genes (maternal effect)Usually refers to gene products deposited in the egg, known as cytoplasmic determinants, produced by the mother, that play important roles in early development.https://en.wikipedia. org/wiki/ Maternal_effect
321MeiosisA specialized type of cell division that reduces the chromosome number of a diploid cell by half, usually during the production of sex cells in sexual reproduction. This creates four haploid cells (or discarded nuclei) which are each genetically distinct from the diploid parent cell that gave rise to them.https://en.wikipedia. org/wiki/Meiosis
322Membrane (lipid bilayer)A selective barrier which allows some things to pass through but stops others. Biological membranes usually consist of lipid bilayers, and may include cell membranes, nuclear membranes, or membranes of organelles in eukaryotic cells, or internal membranes in prokaryotic cells.https://en.wikipedia. org/wiki/Membrane
323Mendelian genetics (Mendelian inheritance)The study of a type of biological inheritance that follows the laws originally proposed by Gregor Mendel in 1865 and 1866 and re-discovered in 1900. When Mendel’s theories were integrated with the Boveri–Sutton chromosome theory of inheritance by Thomas Hunt Morgan in 1915, they became the core of classical genetics.https://en.wikipedia. org/wiki/ Simple_Mendelian_ genetics_in_humans
324Meristematic (meristem)Pertaining to the tissue in most plants containing undifferentiated cells (meristematic cells), found in zones of the plant where growth can take place. Meristematic cells give rise to various organs of a plant and are responsible for growth.https://en.wikipedia. org/wiki/Meristem
325Messenger RNA (mRNA)A large family of RNA molecules that convey genetic information from DNA to the ribosome. Messenger RNA is transcribed from DNA sequences and then processed to produce mature messenger RNA molecules. At the ribosome, they specify the amino acid sequence of the protein products of gene expression.https://en.wikipedia. org/wiki/ Messenger_RNA
326Metabolic pathwayA linked series of chemical reaction occurring within a cell.https://en.wikipedia. org/wiki/ Metabolic_ pathway
327Metabolic scrapyardA metaphor describing the modular reuse of specific enzymes and biochemical pathways in different species and in different ecological contexts.https://en.wikipedia. org/wiki/Metabolism
328MetabolismA general term for the breakdown (catabolism) and synthesis (anabolism) of organic molecules by living organisms. Includes highly conserved core pathways involved with energy capture and conversion, as well as biosynthesis.https://en.wikipedia. org/wiki/Metabolism
329MetabolomicsThe scientific study of chemical processes involving metabolites, the small molecule intermediates and products of metabolism. Specifically, metabolomics is the “systematic study of the unique chemical fingerprints that specific cellular processes leave behind”, the study of their small-molecule metabolite profiles. The metabolome represents the complete set of metabolites in a biological cell, tissue, organ, or organism, which are the end products of cellular processes.https://en.wikipedia. org/wiki/ Metabolomics
330MetalA material that has a lustrous appearance and conducts electricity and heat. A material that has a lustrous appearance and conducts electricity and heat. Metals are typically malleable or ductile. Metals may contain one or more elements. For example, iron is single element, but steel usually contains a mixture of iron plus other elements.https://en.wikipedia. org/wiki/Metal
331MethanogenesisThe formation of methane by methanogens. This is responsible for significant amounts of natural gas accumulations, including atmospheric methane.https://en.wikipedia. org/wiki/ Methanogenesis
332MethanogensMicroorganisms that produce methane as a metabolic byproduct in low oxygen conditions.https://en.wikipedia. org/wiki/ Methanogen
333Micro-machineA metaphorical description of the complex and precise structural and functional roles played by macromolecular interactions, especially proteins.https://en.wikipedia. org/wiki/ Micromachinery
334Microbial consortiumTwo or more microbial groups living symbiotically. Consortia can be endosymbiotic or ectosymbiotic.https://en.wikipedia. org/wiki/ Microbial_ consortium
335MicroevolutionRefers primarily to changes in the frequencies of alleles in the gene pool recognized by Population Genetics. These include the same adaptations that accumulate over evolutionary time and distinguish organisms. The distinction between macroevolution and microevolution is an artificial distinction, because both are part of a natural continuum of change involving both genotypes and phenotypes.https://en.wikipedia. org/wiki/ Microevolution
336MimicryEvolutionary adaptations in which organisms resemble other organisms, usually to mislead potential predators or prey. For example, certain caterpillars have a striking appearance resembling venomous snakes, and are called snake mimics.https://en.wikipedia. org/wiki/Mimicry
337MitochondrionA double-membrane-bound organelle found in most eukaryotic cells. Metabolizes glucose or other sugars and generates most of the cell’s supply of ATP during aerobic respiration.https://en.wikipedia. org/wiki/ Mitochondrion
338MitosisThe part of the cell division cycle of eukaryotes. Usually, identical copies of replicated chromosomes are separated into two new nuclei of daughter cells.https://en.wikipedia. org/wiki/Mitosis
339Modern synthesisEarly 20th century evolutionary synthesis reconciling Charles Darwin’s classical theory of Natural Selection with Mendelian Genetics.https://en.wikipedia. org/wiki/ Modern_synthesis_ (20th_century)
340Module (biology)A general term describing an entity that serves as both a unit of structure and function and a subunit that contributes to more complex emergent structures and functions. Evolutionary modification and reuse of modular genomic elements and their gene products is widely observed in natural history, and is an important theme in evolutionary developmental biology (evo-devo).https://en.wikipedia. org/wiki/Module
341MolarityA measure of the concentration of a chemical species in terms of amount of substance per unit volume of a solution.https://en.wikipedia. org/wiki/Molar_ concentration
342MoleThe unit of measurement for amount of a substance. Specifically, a mole contains 6.02  1023 particleshttps://en.wikipedia. org/wiki/Mole_ (unit)
343Molecular cloning technology (recombinant DNA)A set of experimental methods in molecular biology that are used to assemble recombinant DNA molecules. Can also refer to replication of DNA within host organisms.https://en.wikipedia. org/wiki/Molecular_ cloning
344Molecular evolutionA general term describing all kinds of changes in the DNA sequences of genomes of various species over time.https://en.wikipedia. org/wiki/ Molecular_evolution
345Molecular geneticsThe field of biology that studies the structure and function of genes at a molecular level. Employs methods of molecular biology, including recombinant DNA technology, biochemistry, and genetics.https://en.wikipedia. org/wiki/ Molecular_genetics
346Molecular recognition (biology)In biology, a metaphorical description of shape-specific binding events, such as binding of enzymes and their reactants (substrates), binding of antibodies to specific epitopes of antigens, or binding of signals to cell-surface receptors. The metaphor has teleological overtones, however. Rethinking Evolution introduces a more objective and descriptive term: Shape-specific Molecular Interaction and Binding Events, abbreviated as SSM-IBE.https://en.wikipedia. org/wiki/ Molecular_ recognition
347MoleculeAn electrically neutral group of two or more atoms held together by covalent chemical bonds.https://en.wikipedia. org/wiki/Molecule
348Monoclonal antibodyAn artificially produced, highly specific antibody produced by fusion of a B cell clone with a tumor cell to create a hybridoma. Monoclonal antibodies are extremely valuable reagents in biomedical research, because they recognize highly-specific epitopes (binding portions) of highly-specific antigens, can be produced in very large quantities, and can be tagged with molecules such as fluorescent proteins. They also can sometimes be used to deliver toxins to tumor cells with reduced toxicity for normal cells.https://en.wikipedia. org/wiki/Molecule
349Monomer (biology)A subunit molecule that can undergo polymerization. In biological polymers, monomers of DNA or RNA are nucleotides, monomers of carbohydrates are sugars, and monomers of protein chains are amino acids.https://en.wikipedia. org/wiki/Monomer
350MorphogenUsually, a substance such as a diffusible protein or a specific RNA sequence, that forms a gradient in a developing embryo, leading to particular developmental switches, segmentation patterns, or other aspects of pattern formation that help determine the morphology (shape, structure, and appearance) of organisms during development. Some morphogens are transcription factors.https://en.wikipedia. org/wiki/Morphogen
351Morphogenetic fieldA region in which a coordinated pattern is established during development. Can refer to various aspects of morphology, such as shape, segmentation, or other aspects structure and appearance of an organism. Morphogenic fields are often influenced by morphogens.https://en.wikipedia. org/wiki/ Morphogenetic_field
352Morphology (biology)A general term describing shape and form and structure and function in biology. Usually refers to multicellular structures involving tissues and organshttps://en.wikipedia. org/wiki/ Morphology_ (biology)
353Mosaic embryo (determinate cleavage)A type of embryonic cleavage in which cytoplasmic determinants combined with cell lineage define patterns of cell differentiation, rather than intercellular communication between neighboring embryonic cells (blastomeres).https://en.wikipedia. org/wiki/ Cleavage_(embryo)
354 mRNA (messenger RNA)Processed RNA transcripts that carry sequences of codons (triplets in the nucleotide sequence) to ribosomes, where they determine the amino acid sequences of newly synthesized protein chains.https://en.wikipedia. org/wiki/ Messenger_RNA
355Multicellular (organism)Organisms (generally eukaryotic) composed of multitudes of cells. Includes animals, plants, and fungi. In sexual reproduction of plants and animals, specialized cells arise by cleavage and subsequent development of an embryo derived from a fertilized ovule or egg (zygote), respectively, during development.https://en.wikipedia. org/wiki/ Multicellular_ organism
356Multigene family (gene family)Genes that arise by gene duplication. Most of the genes of multicellular organisms are members of multigene families.https://en.wikipedia. org/wiki/ Gene_family
357MutagenA physical or chemical agent that changes the genetic material of an organism. Mutagens increase the frequency of mutations above the natural background level.https://en.wikipedia. org/wiki/Mutagen
358Mutation (genetics)The permanent alteration of the nucleotide sequence of a genome. Can occur in an organism, virus, extrachromosomal DNA, or other genetic elements.https://en.wikipedia. org/wiki/Mutation
359MutualismThe way organisms of different species exist in a relationship in which each individual benefits from the activity of the other.https://en.wikipedia. org/wiki/ Mutualism_ (biology)
360Myelin sheath (myelin)Specialized cells containing lipid-rich myelin substances that surround neurons (cells of nervous systems that transmit electrical signals) and provide structural support, as well as electrical insulation.https://en.wikipedia. org/wiki/Myelin
361MyosinA motor protein that uses ATP as an energy source and interacts with actin to generate cell motility.https://en.wikipedia. org/wiki/Myosin
362Natural scienceBranch of science concerned with the description, prediction, and understanding of natural phenomena. Based on empirical evidence from observation and experimentation. Examples include biology, chemistry, and physics.https://en.wikipedia. org/wiki/ Natural_science
363Natural SelectionThe differential survival and reproduction of individuals due to differences in phenotype. It is a key mechanism of evolution, the change due to heritable traits characteristic of a population over generations.https://en.wikipedia. org/wiki/ Natural_selection
364Natural theologyA type of theology that provides arguments for the existence of God based on reason combined with observations from nature.https://en.wikipedia. org/wiki/ Natural_theology
365NaturalismThe scientific belief, supported by empirical observations and experiments, that only natural laws and forces operate in the universe.https://en.wikipedia. org/wiki/ Naturalism_ (philosophy)
366Negative chargeThe physical force exerted by electrons. An equal and opposite positive force is exerted by protons. Negative charges often refers to static electrical forces generated by electrons. In atoms, ions, and molecules, negative charges arise from a relative excess of orbiting electrons in a particular region.https://en.wikipedia. org/wiki/ Electric_charge
367Negative logarithmIn mathematics, the negative of the number obtained with the inverse function to exponentiation. That means the negative logarithm of a given number x is the negative of the exponent to which another fixed number, the base b, must be raised, to produce that number x.https://en.wikipedia. org/wiki/Logarithm
368Neo-DarwinismThe interpretation of Darwinian evolution through Natural Selection, as it had been modified since it was first proposed. The term “neo-Darwinism” may refer to the Modern Synthesis, or more recent evolutionary syntheses.https://en.wikipedia. org/wiki/Neo-Darwinism
369NeofunctionalizationOne of the possible outcomes of functional divergence, occurs when one gene copy, or paralog, takes on a totally new function after a gene duplication event. Neofunctionalization is an adaptive mutation process; meaning one of the gene copies must mutate to develop a function that was not present in the ancestral gene. In other words, one of the duplicates retains its original function, while the other accumulates molecular changes such that, in time, it can perform a different task.https://en.wikipedia. org/wiki/ Neofunctionalization
370NicheThe way of life of an organism—how it survives and reproduces in the context of specific environments.https://en.wikipedia. org/wiki/Niche
371Nitrogenous baseAn organic molecule with a nitrogen atom that has the chemical properties of a base. Involved in the base-pairing (hydrogen bonding of complementary bases) of DNA and/or RNA strands.https://en.wikipedia. org/wiki/ Nitrogenous_base
372Nonrepetitive DNA sequencesDNA segments with complex sequences, that is, that lack simple runs of nucleotides or tandem repeats. Usually, protein-coding sequences of DNA (e.g. eukaryotic exons) are relatively nonrepetitive.https://en.wikipedia. org/wiki/ Repeated_sequence_ (DNA)
373Nonspontaneous (chemistry)In chemistry, a nonspontaneous reaction or process requires an external source of energy to drive it. Refers to endergonic chemical reactions. May also refer to the movement of heat or other energy sources, or particles in solutions, from regions where they are lower in amount or concentration to regions that are higher in amount or concentration.https://en.wikipedia. org/wiki/ Endergonic_reaction
374Noncoding DNAComponents of an organism’s DNA that are not transcribed into RNA molecules and/or translated into amino acid sequences of protein chains.https://en.wikipedia. org/wiki/Non-coding_DNA
375NonmetalA chemical element that mostly lacks metallic attributes. Tends to have low melting and boiling points and usually is poor conductor of heat and electricity.https://en.wikipedia. org/wiki/Nonmetal
376Nonrandom (variation or events)Variation or events that are influenced in some way by other factors such that various possible outcomes do not have equal probabilities.https://en.wikipedia.org/wiki/Randomness
377NuanceSubtle, fine, or minor distinction, usually made clear by the precise use of language.https://en.wiktionary. org/wiki/nuance
378Nucleated (cell)A typical eukaryotic cell, which has a nucleus surrounded by membranes (nuclear envelope). Some specialized eukaryotic cells, such as red blood cells in human adults, lose their nuclei during development and are no longer nucleated cells.https://en.wikipedia. org/wiki/ Cell_nucleus
379Nucleic acid (DNA, RNA)Macromolecules of DNA or RNA consisting of polymers of nucleotides. May consist of single or double strands. DNA is the genetic material of all types of cells.https://en.wikipedia. org/wiki/ Nucleic_acid
380Nucleic acid hybridizationA phenomenon in which single-stranded DNA and/or RNA molecules are base-paired to form hybrid double-stranded structures. An essential tool for finding or tagging related (homologous) sequences in biotechnology.https://en.wikipedia. org/wiki/ Nucleic_acid_ hybridization
381Nucleic acid structure (DNA and RNA)Refers to the covalent bonding between nucleotides in strands of DNA or RNA, as well as the 3D structures formed by hydrogen bonds during base-pairing. Both RNA and DNA strands have “backbones” of covalently bonded sugar and phosphate groups, which are covalently bonded to nitrogenous bases.https://en.wikipedia. org/wiki/ Nucleic_acid_ structure
382NucleotideOrganic molecules that serve as the monomer units for forming DNA and RNA. These are the building blocks of nucleic acids and play a central role in metabolism.https://en.wikipedia. org/wiki/Nucleotide
383Nucleotide sequenceA sequence of nucleotides within a strand of DNA or RNA. Nucleotide sequence is determined by the sequence of nitrogenous bases in the nucleotides. Letters are used to represent the different nucleotides. (See A, C, G, T for DNA or A, C, G, U for RNA).https://en.wikipedia. org/wiki/ Nucleic_acid_ sequence
384Nucleus (cell)A structure in eukaryotic cells surrounded by a nuclear envelope consisting of a double lipid bilayer that contains nuclear pores through which molecules are transported to and from the cytoplasm in a regulated way. The nucleus contains chromosomes containing genomic DNA, histone proteins, and other proteins and RNA molecules.https://en.wikipedia. org/wiki/ Cell_nucleus
385NutrientsSubstances used by an organism to survive, grow, and reproduce. Nutrients are used as raw materials and enzymatic co-factors in metabolism.https://en.wikipedia. org/wiki/Nutrient
386Odorant receptors (olfactory receptors)Members of the G protein-coupled receptor gene family involved in signal transduction pathways that detect specific odors. Larger numbers of these receptors are associated with species (such as dogs) that have a keen or highly sensitive/selective sense of smell.https://en.wikipedia. org/wiki/ Olfactory_receptor
387One gene, one enzyme hypothesisThe hypothesis that each gene acts through the production of an enzyme. Each gene is considered to be responsible for producing a single enzyme that in turn affects a single step in a metabolic pathway.https://en.wikipedia. org/wiki/One_ gene%E2%80%93 one_enzyme_ hypothesis
388One gene, one protein chainThe hypothesis that each gene acts through the production of a protein, or more specifically, a particular chain of amino acids (polypeptide). This broadens the “one gene, one enzyme” hypothesis to include any polypeptide. Each gene is considered to be responsible for producing a single protein. True for many genes, but some eukaryotic genes may produce multiple gene products per gene, through alternative splicing during messenger RNA production.
https://en.wikipedia.org/wiki/One_ gene%E2%80%93one_enzyme_ hypothesis
389OperatorIn prokaryotes, a sequence of DNA to which a repressor binds. When the repressor is bound, nearby genes that are downstream cannot be transcribed. A classic example of regulation of gene expression and regulatory DNA sequences.https://en.wikipedia.org/wiki/Operon
390OperonA set of genes containing an operator, involved in the control of expression (transcription) of those genes in response to conditions, such as the availability of a particular sugar, and the need to metabolize that sugar when present.https://en.wikipedia. org/wiki/Operon
391Order (biological organization)In biology, the organized hierarchy of complex biological structures, functions, and systems, that helps to define the complexity of life in terms of simpler ideas. This is a fundamental premise for numerous areas of scientific research.(not applicable)
392Organ (anatomy)Structural and functional arrangement of tissues to perform useful tasks for a multicellular organism.https://en.wikipedia. org/wiki/ Organ_(anatomy)
393OrganelleA specialized subunit within a cell that has a specific function vital to the cell. Usually contains one or more biological membranes. Examples of eukaryotic organelles include mitochondria and chloroplasts.https://en.wikipedia. org/wiki/Organelle
394Organic (chemistry)Pertaining to molecules containing carbon, other than simple molecules such as carbon dioxide or allotropes of carbon, e.g. graphite.https://en.wikipedia. org/wiki/Organic
395Organic compoundAny chemical compound (other than carbon dioxide or pure carbon) that contains carbon atoms.https://en.wikipedia. org/wiki/ Organic_compound
396Organic synthesisSynthesis of organic, i.e. carbon-containing, compounds.https://en.wikipedia. org/wiki/ Organic_synthesis
397Organismic systems approach(evo-devo)In evolutionary developmental biology (evo-devo), a supplement to the Modern Synthesis discussed in a published paper by Callebaut, Müller and Newman.https://www. researchgate.net/ publication/ 258236066_The_organismic_ systems_approach_ EvoDevo_and_the_ streamlining_of_ the_naturalistic_agenda
398Organization (biology)The hierarchy of complex biological structures and systems that define life using a reductionist approach. Each level in the hierarchy represents an increase in organizational complexity, with each “object” being primarily composed of the previous level’s basic unit. The basic principle behind the organization is the concept of emergence—the properties and functions found at a hierarchical level are not present and irrelevant at the lower levels.(not applicable)
399Origin of life (biology)Field of biological research and theory concerned with the first appearance of life forms from nonliving metabolic processes, primary on Earth. Also called abiogenesis. When extended to other planets in the universe, this is generally called astrobiology.https://en.wikipedia. org/wiki/ Abiogenesis
400OxidationA chemical process that removes electrons (or removes hydrogen atoms and electrons) from atoms, molecules, or ions, thereby increasing the positive charge or reducing the negative charge and/or increasing the oxidation state of that substance.https://en.wikipedia. org/wiki/Redox
401Pair-rule geneA type of gene involved in the development of the segmented embryos of insects. Pair-rule genes are expressed as a result of differing concentrations of gap gene proteins, which encode transcription factors controlling pair-rule gene expression. Pair-rule genes are defined by the effect of a mutation in that gene, which causes the loss of the normal developmental pattern in alternating segments. Pair-rule genes were first described by Christiane Nüsslein-Volhard and Eric Wieschaus in 1980.https://en.wikipedia. org/wiki/Pair-rule_gene
402Paradigm shiftA fundamental change in the basic concepts and experimental practices of a scientific discipline.https://en.wikipedia. org/wiki/ Paradigm_shift
403Parasitism (parasitic)A relationship between species where one organism benefits at the expense of another by living on it or within it. This parasite causes its host some harm and will adapt to its way of life.https://en.wikipedia. org/wiki/Parasitism
404ParsonThe priest of an independent parish church. This church is not under the control of another organization.https://en.wikipedia. org/wiki/Parson
405PathogenAn organism, virus or prion that causes harm or disease to another organism.https://en.wikipedia. org/wiki/Pathogen
406Pattern formation (developmental biology)The generation of complex organizations of cell fates in space and time. Pattern formation is controlled by genes. The role of genes in pattern formation is an aspect of morphogenesis, the creation of diverse anatomies from similar genes, now being explored in the science of evolutionary developmental biology or evo-devo.https://en.wikipedia. org/wiki/ Pattern_formation
407Pax (genes, evo-devo)Paired box (Pax) genes are a family of genes coding for tissue specific transcription factors containing a paired domain and usually a partial, or in the case of four family members (PAX3, PAX4, PAX6, and PAX7), [1]a complete homeodomain. An octapeptide may also be present. Pax proteins are important in early animal development for the specification of specific tissues, as well as during epimorphic limb regeneration in animals capable of such.https://en.wikipedia. org/wiki/Pax_genes
408Potential Biological Evolution (PBE)A term introduced in Rethinking Evolution to describe potential change in the heritable characteristics of biological populations over successive generations. As is the case with potential energy, PBE is considered real, not imagined, and dependent on the relative positions and properties of interacting objects.(not applicable)
409Prebiotic or primordial soup hypothesis (PBS)Abbreviation for a hypothetical condition of the Earth’s atmosphere and oceans before the emergence of life. According to this hypothesis, life arose from biological molecules that were formed by spontaneous natural sources of energy such as lightning, heat, or UV irradiation.https://en.wikipedia. org/wiki/ Primordial_soup
410Polymerase chain reaction (PCR)A widely used, rapid, and sensitive technique in biotechnology involving amplification (production of large numbers of identical copies) of DNA or RNA sequences by repeated cycles of DNA replication in vitro.https://en.wikipedia. org/wiki/ Polymerase_chain_ reaction
411Peer-review (scientific)The formal evaluation of work by one or more people of similar competence to the producers of the work. Methods are employed to maintain standards of quality and credibility. A standard practice for most formal publications in scientific journals, and an essential tool for success of the scientific method.https://en.wikipedia. org/wiki/ Peer_review
412Persistent conceptual networks (semantic networks)Refers to semantic relations between concepts that tend to continue for long periods of time. Persistent conceptual networks often influence thoughts and ideas in subtle and subjective ways.https://en.wikipedia. org/wiki/ Semantic_network
413pHA logarithmic scale used to specify the acidity or basicity of an aqueous (water-based) solution. Neutral solutions have a pH of 7.0, whereas acidic solutions and basic solutions have lower and higher pH, respectively.https://en.wikipedia. org/wiki/PH
414PhenotypeThe composite of an organism’s observable characteristics or traits. Results from the expression of an organism’s genetic code, and usually involves complex interactions between multiple genes and gene products.https://en.wikipedia. org/wiki/Phenotype
415Phenotypic gestaltA general term referring to the overall phenotype of an organism that results from numerous genetic determinants that arise as a unified whole from complex molecular, cellular, and developmental interactions.https://en.wikipedia. org/wiki/Phenotype
416PhenylalanineAn amino acid that contains a side-chain with a benzyl functional group.https://en.wikipedia. org/wiki/ Phenylalanine
417Phosphate backbone (sugar-phosphate backbone, DNA or RNA)The covalently bonded phosphate and sugar residues that form an alternating “backbone” in DNA and RNA strands.https://en.wikipedia. org/wiki/ Nucleic_acid_ structure
418PhospholipidsA class of lipids containing a phosphate functional group that are major components of all cell membranes. They are usually found in lipid bilayers.https://en.wikipedia. org/wiki/ Phospholipid
419Photoreceptor proteinLight-sensitive transmembrane G-protein coupled receptor proteins involved in light perception in tissues such as the retina.https://en.wikipedia. org/wiki/ Photoreceptor_ protein
420PhotosynthesisMetabolic process that uses energy from light plus carbon dioxide and water to produce glucose and other sugars. Converts energy into excited electrons, photon gradients, ATP, and NADPH. Takes place in the chloroplasts of plants and in cyanobacteria.https://en.wikipedia. org/wiki/ Photosynthesis
421PhylogenomicsThe intersection of the fields of evolution and genomics. Four major areas fall under phylogenomics: (1) prediction of gene function, (2) establishment and clarification of evolutionary relationships, (3) gene family evolution, and (4) prediction and retracing lateral gene transfer.https://en.wikipedia. org/wiki/ Phylogenomics
422Pigmentation (biological pigment)A light-absorbing substance produced by a living cell. The colors of pigments are derived from wavelengths of light that are not absorbed by the pigment.https://en.wikipedia. org/wiki/ Biological_pigment
423PlantOne of the three kingdoms of multicellular organisms. Plant cells are distinguished from animal cells by cell walls and must add to the cell wall with the cell plate to divide. Plant cells usually perform photosynthesis which takes place in chloroplasts, and often have large vacuoles in the cytoplasm that can store fluids and contribute to the turgidity of the cell.https://en.wikipedia. org/wiki/Plant
424PlasmidA small circular DNA molecule within a cell. Physically separated from chromosomal DNA and can replicate independently.https://en.wikipedia. org/wiki/Plasmid
425PlastidA membrane-bound organelle found in the cells of plants, algae, and some other eukaryotic organisms. Plastids are the site of manufacture and storage of important chemical compounds used by the cells of autotrophic eukaryotes. They often contain pigments used in photosynthesis, and the types of pigments in a plastid determine the cell’s color. They have a common evolutionary origin and possess a double-stranded DNA molecule that is circular, like that of prokaryotic cells.https://en.wikipedia. org/wiki/Plastid
426PleiotropicEffects caused by single genes that influence two or more seemingly unrelated observable traits.https://en.wikipedia. org/wiki/Pleiotropy
427Point mutationA genetic mutation that changes the identity of a single nitrogenous base in a DNA sequence. May result in a change in one codon, which may change a single amino acid or add or eliminate a start or stop codon in a protein-coding sequence.https://en.wikipedia. org/wiki/ Point_mutation
428Polar (bond)An electric dipole resulting from differential attraction of the electron cloud of a hybrid orbital toward two atomic nuclei that have different effective positive nuclear charges in a hybrid orbital. The differential attraction results from differences in the effective positive nuclear charge of the two atomic nuclei.https://en.wikipedia. org/wiki/ Chemical_polarity
429Polar (molecule)A molecule with one or more polar bonds with an asymmetrical surrounding charge distribution. Often, this results from polar bonds combined with VSEPR from lone pairs of electrons (VSEPR valence shell electron pair repulsion).(not applicable)
430Polar bondsAsymmetrical positive and negative charge distribution resulting from asymmetrical distribution of electrons in hybrid orbitals of covalent bond. Arise when elements with relatively large and small effective nuclear charges, such as hydrogen and oxygen, form covalent bonds. Results from greater pull on electron cloud by nucleus with larger effective nuclear charge.https://en.wikipedia. org/wiki/ Chemical_polarity
431Polar moleculesMolecules with local asymmetrical positive and negative charge distributions that result from the combination of polar bonds and other sources of asymmetry in the overall molecular shape, such as lone pairs and VSEPR (valence shell electron pair repulsion). Symmetrical molecules with polar bonds are not polar molecules.https://en.wikipedia. org/wiki/ Chemical_polarity
432Pollination vectorUsually refers to an animal that transfers pollen from a male part of a plant to a female part of a plant. This enables fertilization and seed production by the plant.https://en.wikipedia. org/wiki/Pollination
433Polymer (biology)A large molecule composed of many repeated subunits which are called monomers. Major classes of biological polymers include nucleic acids (DNA and RNA, protein chains, and glucose polymers such as cellulose, starch, glycogen, and chitin.https://en.wikipedia. org/wiki/Polymer
434Polymerase chain reaction (PCR)A technique used in molecular biology to artificially amplify a specific segment of a DNA or RNA template. Starting with one or more template molecules, amplification rapidly and routinely generates hundreds of thousands or millions of identical copies. RNA amplification often involves starting with a complementary DNA sequence generated from the RNA.https://en.wikipedia. org/wiki/ Polymerase_chain_ reaction
435Polytene chromosomeLarge chromosome that has thousands of identical DNA strands that have not separated by mitosis. They provide a high level of function in certain tissues.https://en.wikipedia. org/wiki/ Polytene_ chromosome
436Population geneticsA subfield of genetics that deals with genetic differences (especially, allele frequencies) within and between populations. It is a part of evolutionary biology.https://en.wikipedia. org/wiki/ Population_genetics
437PorosityA measure of the openings (void spaces) in a material. This determines the ability of other substances to pass through a porous material. Porosity is expressed as a fraction of the volume of voids over the total volume.https://en.wikipedia. org/wiki/Porosity
438PorousContaining spaces that allow substances to pass through.https://en.wikipedia. org/wiki/Porosity
439Position-effect variegationLocal effects in gene expression caused by nearby genetic elements. Often caused by transposable elements, which have randomly inserted themselves in the genome in different cells. A visible phenotypic effect is the diverse and random color pattern found in the seeds of maize. Reported by Nobel Laureate Barbara McClintock.https://en.wikipedia. org/wiki/ Position-effect_ variegation
440Positive chargeA static electric charge associated with the subatomic proton particle. In atoms, molecules, or ions, can be caused by a deficit of negative charges from electrons.https://en.wikipedia. org/wiki/ Electric_charge
441Potential (possibility of specific changes or events)In general terms, potential describes the possibilities and probabilities of subsequent events. Potential can be changed by actual events.https://en.wikipedia. org/wiki/Potential
442Potential Biological EvolutionA term introduced in Rethinking Evolution to describe potential change in the heritable characteristics of biological populations over successive generations. As is the case with potential energy, PBE is considered real, not imagined, and dependent on the relative positions and properties of interacting objects.(not applicable)
443Potential energyIn physics, potential energy represents energy that results from relative positions, such as a pencil held over a table. In chemistry, potential energy is found in covalent bonds and in differential concentrations of particles, such as proton gradients.https://en.wikipedia. org/wiki/ Potential_energy
444Prebiotic soup (primordial soup)A hypothetical condition of the Earth’s atmosphere and oceans before the emergence of life. According to this hypothesis, life arose from biological molecules that were formed by spontaneous natural sources of energy such as lightning, heat, or UV irradiation.https://en.wikipedia. org/wiki/ Primordial_soup
445PrecipitateA verb describing the separation of a dissolved substance from a solution, or a noun describing the state of that substance. Precipitates include solids, such as salts for example, or liquids, such as droplets of rain.https://en.wikipedia. org/wiki/ Precipitation_ (chemistry)
446PrecipitationThe formation of a precipitate, such as solids crystallizing out of solution or the formation of rain droplets (see precipitate).https://en.wikipedia. org/wiki/ Precipitation_ (chemistry)
447Preformationism (sperm)The false belief that tiny individuals, such as miniature human individuals, can be found, preformed, in sperm cells.https://en.wikipedia. org/wiki/ Preformationism
448PressureThe force applied perpendicular to the surface of an object.https://en.wikipedia. org/wiki/Pressure
449Primary producer (autotroph)Uses energy in light or in inorganic chemical compounds to build organic molecules.https://en.wikipedia. org/wiki/ Primary_producers
450Primary structureThe shape and characteristics determined by the linear sequence of amino acids in a protein chain, which also helps determine higher-level structure.https://en.wikipedia. org/wiki/ Protein_primary_ structure
451Producer (autotroph)An organism such as a plant that can build macromolecules from simple elements such as carbon dioxide and water. Photoautotrophs use the energy of sunlight to do this; chemoautotrophs use energy of inorganic compounds from the environment. In ecosystems, producers such as plants generate excess carbohydrates and other materials that can be used as energy and nutrient sources by consumers (heterotrophs).https://en.wikipedia. org/wiki/Autotroph
452Products (chemistry)The substances resulting from a chemical reaction.https://en.wikipedia. org/wiki/Product_ (chemistry)
453Programmed cell deathProgrammed cell death (or PCD) is the death of a cell in any form, mediated by an intracellular program. PCD is carried out in a biological process, which usually confers advantage during an organism’s life-cycle. PCD serves fundamental functions during both plant and animal tissue development as well as the removal of infected, genetically damaged, or cancerous cells.https://en.wikipedia. org/wiki/ Programmed_ cell_death
454Prokaryotic (prokaryote)Major classification of living cells that includes bacteria and archaea, but not eukaryotes. Prokaryotes are usually found as unicellular organisms that lack nuclei and membrane-bound organelles.https://en.wikipedia. org/wiki/Prokaryote
455ProteinMacromolecule consisting of one or more long covalently bound chains of amino acid residues. Protein molecules perform a vast array of functions within all organisms.https://en.wikipedia. org/wiki/Protein
456Protein chainA covalently bound chain of specific amino acid residues that constitute a specific protein chain. Amino acid residues are joined by peptide bonds formed between amino groups and carboxyl groups of adjacent amino acids.https://en.wikipedia. org/wiki/Protein
457Protein sequence (amino acid sequence)A covalently bound chain of specific amino acid residues that constitute a specific protein chain.https://en.wikipedia. org/wiki/ Protein_sequencing
458Protein synthesisThe process whereby biological cells generate new protein chains by transcription and translation.https://en.wikipedia. org/wiki/ Protein_biosynthesis
459Protein-codingSequences of DNA that determine the amino acid sequences of proteins.https://en.wikipedia. org/wiki/Gene
460ProtonA positively charged subatomic particle found in the nucleus of all atoms. Proton number defines the identity of a chemical element. A single proton is found in the nucleus of hydrogen, so ionized hydrogen atoms are equivalent to protons.https://en.wikipedia. org/wiki/Proton
461Proton gradientAn unequal distribution of protons (hydrogen ions), often across some sort of barrier such as a cell membrane, that represent potential energy. Proton gradients at undersea alkaline hydrothermal mounds (UAHM) are also hypothesized to have played an important role in the origin of life on Earth.https://en.wikipedia. org/wiki/ Electrochemical_ gradient
462Protozoan (protozoa)Informal term for single-celled eukaryotes, either free-living or parasitic, which feed on organic matter such as other microorganisms or organic tissues and debris.https://en.wikipedia. org/wiki/Protozoa
463PseudoscienceBeliefs and ideas that have the appearance of science, but are not actually based on genuine logic, empirical evidence, or the scientific method. Pseudoscience may be propagated either deliberately or unwittingly. Often, pseudoscience is spread by special interest groups that have political, economic, discriminatory, or religious agendas.https://en.wikipedia. org/wiki/ Pseudoscience
464Q-cycleA series of reactions describing how the sequential oxidation and reduction of electron carriers result in the movement of protons across a lipid bilayer.https://en.wikipedia. org/wiki/Q_cycle
465Quantitative inheritanceA branch of population genetics that deals with phenotypes that vary continuously (in characters such as height or mass)—as opposed to discretely identifiable phenotypes and gene-products (such as eye-color, or the presence of a particular biochemical).https://en.wikipedia. org/wiki/ Quantitative_ genetics
467Quaternary structureThe 3D shape formed when two or more folded protein chains bind together. Many functional proteins have multiple protein chains.https://en.wikipedia. org/wiki/Protein_ quaternary_structure
468QuinoneA class of organic compounds that are formally derived from aromatic compounds. Occurs by converting CH groups into C(O) groups.https://en.wikipedia. org/wiki/Quinone
469Quorum sensing (bacteria)The ability to detect and to respond to cell population density by gene regulation. As one example, quorum sensing (QS) enables bacteria to restrict the expression of specific genes to the high cell densities at which the resulting phenotypes will be most beneficial. Many species of bacteria use quorum sensing to coordinate gene expression according to the density of their local population.https://en.wikipedia. org/wiki/ Quorum_sensing
470QWERTY keyboard layoutA widely-used standard arrangement of characters on both mechanical and virtual or digital keyboards. The name comes from the order of the first six keys on the top left letter row of the keyboard.https://en.wikipedia. org/wiki/QWERTY
471Random fertilizationThe random union of one of many possible egg and sperm cells during sexual reproduction.https://en.wikipedia.org/wiki/Quantitative_genetics
472Random mutationA heritable change in a DNA sequence where the different possible changes have equal probabilities.https://en.wikipedia. org/wiki/Mutation
473Random shuffling of genomic sequences (genetic recombination)In genetic recombination, random crossover events that take place during meiosis that result in recombinant chromosomes that have portions of maternal and paternal sequences. Although crossover events are relatively random with respect to the loci involved, repetitive sequences are often hotspots for recombination.https://en.wikipedia. org/wiki/ Genetic_ recombination
474Random variation (genetics)Genotypic and phenotypic variation in which the variants have equal probabilities of occurrence by random chance alone.https://en.wikipedia. org/wiki/ Genetic_variation
475Raw material (chemistry or biology)Basic material, including reactants or energy sources, that can be transformed by natural processes into products or other material.https://en.wikipedia. org/wiki/ Raw_material
476Reactant (reagent)A chemical substance that undergoes a chemical reaction and is transformed into product substances.https://en.wikipedia. org/wiki/Reagent
477Receptor (biochemistry)A protein molecule that receives chemical signals from outside a cell. When such chemical signals bind to a receptor, they cause some form of cellular/tissue response, e.g. a change in the electrical activity of a cell.https://en.wikipedia. org/wiki/ Receptor_ (biochemistry)
478RecessiveA Mendelian genetic relationship between alleles of a gene, in which the phenotype of one allele is masked or hidden in the presence of another allele, which is dominant.https://en.wikipedia. org/wiki/ Dominance_ (genetics)
479Recognition sequenceA DNA sequence motif that binds to another molecule, such as a restriction enzyme, in a specific manner.https://en.wikipedia. org/wiki/ Recognition_ sequence
480Recombinant DNADNA molecules formed by laboratory methods of genetic recombination. The technology that combines genetic material from multiple sources, creating artificial sequences not usually found in nature.https://en.wikipedia. org/wiki/ Recombinant_DNA
481Recombination (meiosis)Exchanges between sister chromatids of homologous chromosomes that result in recombinant chromosomes containing some segments inherited from the father and some from the mother. Occurs in a somewhat random fashion during meiosis, which produces sex cells.https://en.wikipedia. org/wiki/ Recombination
482Recombination-activating geneGenes that encode enzymes that play an important role in the rearrangement and recombination of the genes of immunoglobulin and T cell receptor molecules, however there is no evidence to suggest the developing T cells can undergo receptor editing in the same way that B cells do.https://en.wikipedia. org/wiki/ Recombination-activating_gene
483Redox (reaction)A chemical reaction involving exchanges of electrons between atoms or molecules, in which one substance is reduced (gains electrons) while the other is oxidized (loses electrons).https://en.wikipedia. org/wiki/ Recombination-activating_gene
484ReductionA chemical process that adds electrons (or adds hydrogen atoms and electrons) to atoms, molecules, or ions, thereby increasing the negative charge or reducing the positive charge and/or decreasing the oxidation number of that substance.https://en.wikipedia. org/wiki/Reduction
485Reduction potentialA measure of the tendency of a chemical species to acquire electrons and thereby be reduced. The more positive the potential, the greater its tendency is to be reduced.https://en.wikipedia. org/wiki/ Reduction_potential
486Regional specificationThe process whereby regions of the embryo respond to signals and change their patterns of gene expression in coordinated ways, in response to signals such as morphogens and/or by means of other molecular or cellular interactions during development.(not applicable)
487Regulative embryo (cleavage, indeterminate)Embryos that cleave into cells (blastomeres) that remain flexible in their developmental fates, where cellular interactions help to coordinate the range of different types of specialized cells produced by the daughter cells produced by early divisions.https://en.wikipedia. org/wiki/ Cleavage_(embryo)
488Regulatory sequencesA segment of a nucleic acid molecule which is capable of increasing or decreasing the expression of specific genes within an organism. It is an essential feature of all living organisms and viruses.https://en.wikipedia. org/wiki/ Regulatory_ sequence
489Repeated sequence (genomic DNA)Genomic DNA sequences that occur in multiple copies. Includes simple or complex tandem repeats or nonadjacent repeated elements.https://en.wikipedia. org/wiki/ Repeated_sequence_ (DNA)
490Repetitive DNA sequencesA broad category describing a variety of different types of repetitive genomic sequences.https://en.wikipedia. org/wiki/Category: Repetitive_DNA_ sequences
491Replicate (biology)An exact copy of a biological entity, a laboratory experiment, or samples used in an experiment.https://en.wikipedia. org/wiki/ Replicate_(biology)
492ReplicationGenerally, reproduction of an exact copy of an entity, which may include a gene, a cell, a genome, or other entities.https://en.wikipedia. org/wiki/Replication
493Replication slippage (slipped-strand mispairing)A form of mutation that leads to expansion or contraction of simple repetitive sequences such as dinucleotide or trinucleotide repeats. Occurs during DNA replication.https://en.wikipedia. org/wiki/ Replication_slippage
494Reproductive isolationA collection of evolutionary mechanisms, behaviors, and physiological processes that disrupt gene flow between populations. A common mechanism by which populations evolve into distinct species.https://en.wikipedia. org/wiki/ Reproductive_ isolation
495Res potentia (quantum physics)Refers to a theory advanced by Ruth Kastner, Stuart Kauffman, and Michael Epperson, where potential events in the quantum realm have a real existence, but ordinary concepts of space and time do not apply.https://arxiv.org/ abs/1709.03595
496Restriction enzymeAn enzyme that cleaves DNA into fragments. Depends on binding of the enzyme to specific nucleotide sequence motifs called recognition sites or restriction sites.https://en.wikipedia. org/wiki/ Restriction_enzyme
497RetrovirusA virus that produces reverse transcriptase and uses it to integrate RNA into DNA.https://en.wikipedia. org/wiki/Retrovirus
498Reverse transcriptaseEnzymes that synthesize complementary (base-paired) DNA strands from RNA templates. Discovered in retroviruses (such as HIV) and used in biotechnology.https://en.wikipedia. org/wiki/ Reverse_ transcriptase
499RibosomeA complex molecular micro-machine found within all living cells, consisting of RNA and protein components. The site of biological protein synthesis.https://en.wikipedia. org/wiki/Ribosome
500RNAAbbreviation for ribonucleic acid. Various types of RNA, such as messenger RNA, transfer RNA, and ribosomal RNA are involved in transcription and translation of genetic information, but there are many other types of RNA that have been more recently discovered, that play a variety of roles in the storage, transmission, and expression of genetic information.>RNA sequences have the sugar ribose as part of their backbone, and have nucleotides containing adenine, cytosine, guanine, and uracil nitrogenous bases.https://en.wikipedia. org/wiki/RNA
501RNA polymeraseEnzymes involved in transcription, usually from DNA templates, that synthesize strands of RNA that are complementary to the DNA template.https://en.wikipedia. org/wiki/ RNA_polymerase
502RNA synthesisSynthesis of a complementary (base-paired) RNA strand from a DNA template by RNA polymerase enzymes.https://en.wikipedia. org/wiki/RNA
503RNA world (hypothesis)Refers to a hypothetical stage in the origin of life in which the primary genetic material was RNA rather than DNA.https://en.wikipedia. org/wiki/ RNA_world
504Rube Goldberg device (machine)A Rube Goldberg machine is a machine intentionally designed to perform a simple task in an indirect and overcomplicated fashion. Often, these machines consist of a series of simple devices that are linked together to produce a domino effect, in which each device triggers the next one, and the original goal is achieved only after many steps. In biology, evolutionary processes often generate structures and functions that have the appearance of Rube Goldberg machines, but actually arise by blind natural processes.https://en.wikipedia. org/wiki/ Rube_Goldberg_ machine
505SalinityThe amount of salt in a solution. Salts are ionic substances such as sodium chloride or potassium chloride.https://en.wikipedia. org/wiki/Salinity
506Scanning electron microscopeA type of electron microscope that generates high-resolution images of the surfaces of tiny objects with focused beams of electrons.https://en.wikipedia. org/wiki/ Scanning_electron_ microscope
507Schwann cellNamed after physiologist Theodor Schwann, cell types that are the principal glia of the peripheral nervous system (PNS). Glial cells function to support neurons and in the PNS, also include satellite cells, olfactory ensheathing cells, enteric glia and glia that reside at sensory nerve endings, such as the Pacinian corpuscle. The two types of Schwann cells are myelinating and nonmyelinating.https://en.wikipedia. org/wiki/ Schwann_cell
508Scientific theoryAn explanation of an aspect of the natural world that can be repeatedly tested. Scientific theories are often tested in accordance with the scientific method, using a predefined and reproducible protocol of observations and experiments.https://en.wikipedia. org/wiki/ Scientific_theory
509Secondary messenger (system)Cytoplasmic substances involved in transducing and transmitting signals from cell surface receptors in signal transduction pathways.https://en.wikipedia. org/wiki/ Second_messenger_ system
510Secondary structure (protein)The 3D form of local segments of protein chains (but not the entire folded chain). The most common elements are alpha helices and beta sheets.https://en.wikipedia. org/wiki/ Protein_secondary_ structure
511Secreted protein (secretory protein)A protein that is normally transported outside the cell membrane by normal physiological processes. Usually refers to functional proteins, such as milk proteins or antibodies, rather than waste materials which are referred to as excreted materials.https://en.wikipedia. org/wiki/ Secretory_protein
512Segmentation (biology)The division of some animal and plant body plans into a series of repetitive segments, which are specified during development.https://en.wikipedia. org/wiki/ Segmentation_ (biology)
513Selection (Natural Selection)The natural preservation of variants in a population that prove useful within the context of survival and/or reproduction. A critical component of Natural Selection.https://en.wikipedia. org/wiki/Selection
514Selective advantage (Natural Selection)Variants of structures and functions that are more useful than others in the struggle for existence and therefore tend to be preserved by Natural Selection.https://en.wikipedia. org/wiki/Adaptation
515Selective forces (evolutionary pressure)Environmental factors (both living and nonliving, biotic and abiotic) that act on natural populations to preserve (naturally select) certain variants more than others, because those factors contribute more to survival and reproduction in a particular context.https://en.wikipedia. org/wiki/ Evolutionary_ pressure
516Self-accelerating processAny process that increases in rate. For example, length increases in simple-repetitive sequences by slipped-strand mispairing, can be a self-accelerating process in genomic evolution.https://en.wikipedia. org/wiki/ Acceleration
517Self-organizationA process where some form of overall order arises naturally from local interactions. Interactions between parts of an initially disordered system can result in emergent structures and functions.https://en.wikipedia. org/wiki/Self-organization
518Selfish DNA (selfish genetic element)DNA sequences that replicate and often move around by relatively random and non-Mendelian processes. The teleological term “selfish” refers to the fact that the sequences replicate and insert themselves in genomes by molecular mechanisms that are arbitrary, due to their molecular structure. Transposable elements and retroviruses are examples of selfish DNA.https://en.wikipedia. org/wiki/ Selfish_genetic_ element
519Semantics (linguistics)The subfield that is devoted to the study of meaning, as inherent at the levels of words, phrases, sentences, and larger units of discourse (termed texts, or narratives). The study of semantics is also closely linked to the subjects of representation, reference, and denotation.https://en.wikipedia. org/wiki/Semantics
520Semi-permeableA barrier that selectively lets specific substances or objects through. The ability to pass through is often determined by physical characteristics such as size and/or shape, or by chemical characteristics such as attractive or repulsive forces.https://en.wikipedia. org/wiki/ Permeability
521Semi-permeable membraneA type of biological or synthetic membrane. It will allow certain molecules or ions to pass through by diffusion.https://en.wikipedia. org/wiki/ Semipermeable_ membrane
522SerpentinizationA hydration and metamorphic transformation of ultramafic rock from the Earth’s mantle. The mineral alteration is particularly important at the sea floor at tectonic plate boundaries.https://en.wikipedia. org/wiki/ Serpentinite
523Sex cells (sperm or egg)Sperm or egg cells which are produced by male or female germ line cells, respectively, during meiosis, in sexually reproducing organisms.https://en.wikipedia. org/wiki/Gamete
524Sex chromosomeA chromosome that determines the sex of an individual. Sex chromosomes are designated as X, Y, W, or Z, depending on the mechanism of sex determination.https://en.wikipedia. org/wiki/Sex_ chromosome
525Sex determination (system)Determination of biological gender by genetic elements.https://en.wikipedia. org/wiki/Sex-determination_ system
526Sex-linked (sex-linkage, X-linkageRefers to genes that are located on sex chromosomes. In mammals, sex-linkage usually refers to genes linked to the X chromosome, but can also refer to sequences found on Y chromosomes, or on W or Z sex chromosomes in certain groups of animals such as amphibians.https://en.wikipedia. org/wiki/Sex_ linkage
527Sexual reproductionA form of reproduction in which sex cells (sperm and eggs) fuse together. The cells fuse during fertilization, resulting in a zygote that develops into a new individual.https://en.wikipedia. org/wiki/ Sexual_reproduction
528Sexual selectionA mode of natural selection where members of one biological sex choose mates of the other sex to mate with (intersexual selection), and compete with members of the same sex for access to members of the opposite sex (intrasexual selection). These two forms of selection mean that some individuals have better reproductive success than others within a population, either from being more attractive or preferring more attractive partners to produce offspring.https://en.wikipedia. org/wiki/ Sexual_selection
529Shape-specific Molecular Interaction and Binding Events (SSM-IBE)A descriptive term introduced in Rethinking Evolution referring to highly-specific molecular binding events and interactions between biologically important molecules such as enzymes and their reactants (substrates), antibodies and their specific epitopes of antigens, cell-surface receptors and their signals, and DNA sequences and transcription factors.(not applicable)
530Side-chainA chemical group that is attached to the backbone of a molecule. It is one factor determining a molecule’s properties and reactivity. For example, the 20 types of amino acids found in living cells are distinguished by their side chains.https://en.wikipedia. org/wiki/Side_chain
531Signal peptideSometimes referred to as signal sequence, targeting signal, localization signal, localization sequence, transit peptide, leader sequence or leader peptide), signal peptides are short amino acid sequences (usually 16–30 amino acids long), present at the N-terminus of the majority of newly synthesized proteins, that are destined towards the secretory pathway. These proteins include those that reside either inside certain organelles (the endoplasmic reticulum, Golgi or endosomes), are secreted from the cell, or are inserted into most cellular membranes.https://en.wikipedia. org/wiki/ Signal_peptide
532Signal transductionThe process by which a chemical or physical signal is transmitted, often from a transmembrane cell-surface receptor, through a cell as a series of molecular events, most commonly protein phosphorylation catalyzed by protein kinase enzymes but also by means of other intermediaries such as secondary messengers, which ultimately results in a cellular response.https://en.wikipedia. org/wiki/ Signal_transduction
533Signal transduction pathwayA pathway by which a chemical or physical signal is transmitted, often from a transmembrane cell-surface receptor, through a cell as a series of molecular events, most commonly protein phosphorylation catalyzed by protein kinase enzymes but also by means of other intermediaries such as secondary messengers, which ultimately results in a cellular response.https://en.wikipedia. org/wiki/Cell_ signaling– Signaling_ pathways
534Simple-repetitive DNA sequence (repeated sequence, simple sequence)A sequence containing large numbers of short tandem repeats ranging in length from single nucleotides to several nucleotides.https://en.wikipedia. org/wiki/ Repeated_sequence_ (DNA)
535Single-stranded (not base-paired)Strands of DNA or RNA that are not base-paired with other strands (and do not have substantial internal base-pairing).https://en.wikipedia. org/wiki/Base_pair
536Skeletal muscleOne of three major muscle types, apart from cardiac muscle and smooth muscle. Skeletal muscle refers to multiple bundles (fascicles) of cells joined together called muscle fibers. Muscle fibers are in turn composed of myofibrils. The myofibrils are composed of actin and myosin filaments, repeated units are known as sarcomeres, which are the basic functional units of the muscle fiber.https://en.wikipedia. org/wiki/ Skeletal_muscle
537Slipped-strand mispairingA mutation process in which simple sequence repeat units are added or deleted, usually due to mispairing of tandem repeat units during DNA replication. A major evolutionary source of simple-repetitive DNA sequences, particularly in eukaryotic genomes.https://en.wikipedia. org/wiki/ Slipped_strand_ mispairing
538Social sciencesSciences that are concerned with society and the relationships among individuals within a society. Examples of social sciences include social psychology, sociology, history, and political science.https://en.wikipedia. org/wiki/ Social_science
539SociobiologyA field of biology that aims to examine and explain social behavior of animals in terms of evolution.When applied to humans, great care must be taken to rely on empirical scientific data when drawing conclusions.https://en.wikipedia. org/wiki/ Sociobiology
540SolutionA homogeneous mixture in which a solvent surrounds solute particle at the molecular level.https://en.wikipedia. org/wiki/Solution
541Somatic hypermutation (SHM)A cellular mechanism by which the immune system adapts to the new foreign elements that confront it. A major component of the process of affinity maturation, SHM diversifies B cell receptors used to recognize foreign elements (antigens) and allows the immune system to adapt its response to new threats during the lifetime of an organism. SHM involves a programmed process of mutation affecting the variable regions of immunoglobulin genes. Unlike germline mutation, SHM affects only an organism’s individual immune cells, and the mutations are not transmitted to the organism’s offspring.https://en.wikipedia. org/wiki/ Somatic_ hypermutation
542Sox (gene family)A family of transcription factors with a highly-conserved DNA binding domain called the HMG-box. Homologues have been identified in insects, nematodes, amphibians, reptiles, birds and a range of mammals. HMG boxes called SRY resides on the Y-chromosome and many other different aspects of development in various species of eukaryotic organisms.https://en.wikipedia. org/wiki/ SOX_gene_family
543Sperm cellThe male reproductive cell (sex cell) that develops after a diploid cell from the male germ line undergoes meiosis to form four haploid daughter cells.https://en.wikipedia. org/wiki/Sperm
544Sponge (biology)Members of the phylum Porifera which are multicellular organisms that have bodies full of pores and channels allowing water to circulate through them, consisting of jelly-like mesohyl sandwiched between two thin layers of cells.https://en.wikipedia. org/wiki/Sponge
545Spontaneous mutationA mutation that occurs by chance in a genome in a natural setting.https://en.wikipedia. org/wiki/Mutation
546Spontaneous reaction (chemical)The time-evolution of a chemical system in which it releases free energy. It moves to a lower, more thermodynamically stable energy state.https://en.wikipedia. org/wiki/ Spontaneous_ process
547Sporulation (spore)Formation of spores, which are dormant forms of bacteria, or units of sexual or asexual reproduction in eukaryotes, that may be adapted for dispersal and for survival, often for extended periods of time, in unfavorable conditions.
548Slipped-strand mispairing (SSM)Also known as replication slippage, SSM is a mutation process which occurs during DNA replication. It involves denaturation and displacement of the DNA strands, resulting in mispairing of the complementary bases. When it synergizes with additional mutational mechanisms such as point mutations and unequal crossing-over, offers a comprehensive explanation for the origin and evolution of repetitive DNA sequences.https://en.wikipedia. org/wiki/ Slipped_strand_ mispairing
549Shape-specific Molecular Interactions and Binding Events (SSM-IBE)Descriptive term introduced in Rethinking Evolution referring to highly-specific molecular binding events and interactions between biologically important molecules such as enzymes and their reactants (substrates), antibodies and their specific epitopes of antigens, cell-surface receptors and their signals, and DNA sequences and transcription factors.(not applicable)
550Stability (chemical stability)The tendency of a chemical substance to remain the same rather than undergoing chemical reactions.https://en.wikipedia. org/wiki/ Chemical_stability
551Stem cellA cell that can differentiate into other types of cells and can divide to produce more of the same type of stem cells. They are found in multicellular organisms.https://en.wikipedia. org/wiki/Stem_cell
552Strong chemical bond (covalent bond)A chemical bond that involves sharing of one or more electron pairs in hybrid orbitals, binding atoms together by an electromagnetic force. Strong chemical bonds often require chemical reactions to break them.https://en.wikipedia. org/wiki/ Chemical_bond
553SubfunctionalizationOne of the possible outcomes of functional divergence that occurs after a gene duplication event, in which pairs of genes that originate from duplication, or paralogs, take on separate functions. Subfunctionalization is a neutral mutation process; meaning that no new adaptations are formed.https://en.wikipedia. org/wiki/ Subfunctionalization
554Submicroscopic realmA general term with two general meanings: (1) Describes small objects, such as cells and organelles, that are too small to be resolved with a light microscope. (2) Applies to objects at the atomic or subatomic size scale, which are governed by the laws of quantum mechanics rather than classical physics.https://en.wikipedia. org/wiki/ Microscopic_scale
555Substrate-level phosphorylationA metabolic reaction that results in the formation of ATP or GTP by the direct transfer of a phosphoryl (PO3) group to ADP or GDP from another phosphorylated compound. Unlike oxidative phosphorylation, oxidation and phosphorylation are not coupled in the process of substrate-level phosphorylation.https://en.wikipedia. org/wiki/ Substrate-level_ phosphorylation
556Subunit (biology)Part of a larger entity, called a unit. Subunits usually have structural and functional integrity, but can interact with other subunits to form higher levels of complexity which have emergent properties.https://en.wikipedia. org/wiki/Subunit
557SugarThe generic name for soluble carbohydrates. Simple sugars are called monosaccharides and include glucose (also known as dextrose), fructose, and galactose, as well as five-carbon sugars such as ribose and deoxyribose found in nucleic acids.https://en.wikipedia. org/wiki/Sugar
558SymbiosisAny type of a close and long-term biological interaction between two organisms. This can benefit both organisms, harm one and benefit the other, or benefit one and have no effect on the other.https://en.wikipedia. org/wiki/Symbiosis
559Synthesis (organic)The chemical synthesis of organic compounds from chemical precursors.https://en.wikipedia. org/wiki/Synthesis
560T cellOne of the subtypes of a white blood cell in a vertebrate’s immune system.https://en.wikipedia. org/wiki/ Lymphocyte
561T-cell receptorA molecule found on the surface of T cells, or T lymphocytes, that is responsible for recognizing fragments of antigen as peptides bound to major histocompatibility complex (MHC) molecules. T-cell receptor genes are diverse members of the immunoglobulin superfamily.https://en.wikipedia. org/wiki/T-cell_ receptor
562Tandem arrayA gene cluster created by mechanisms that generate new genetic material. They serve to encode large numbers of genes at a time.https://en.wikipedia. org/wiki/Tandemly_ arrayed_genes
564Temperature-sensitive (mutation)A mutation, usually in a protein-coding gene, whose phenotype is expressed at certain temperatures and not others.https://en.wikipedia. org/wiki/ Temperature-sensitive_mutant
565Template (DNA or RNA)During DNA replication or transcription, a single strand of DNA serves as a template for the synthesis of a complementary (base-paired) strand of DNA or RNA by DNA or RNA polymerase enzymes, respectively. During reverse transcription, a strand of RNA serves as a template for synthesis of a complementary DNA strand by reverse transcriptase.(not applicable)
566Template-based replicationDuring DNA replication or transcription, a single strand of DNA serves as a template for the synthesis of a complementary (base-paired) strand of DNA or RNA by DNA or RNA polymerase enzymes, respectively. During reverse transcription, a strand of RNA serves as a template for synthesis of a complementary DNA strand by reverse transcriptase.(not applicable)
567Tertiary structure (protein)The 3D, usually folded shape of a protein. It will have a single amino acid primary sequence as well as secondary structure.https://en.wikipedia. org/wiki/ Protein_tertiary_ structure
568Tether (molecular)Attach a molecule or molecular structure to a rigid support by means of an intermediate substance.https://en.wikipedia. org/wiki/Tether_(disambiguation)
569TetrapodThe superclass Tetrapoda contains the four-limbed vertebrates known as tetrapods. It includes extant and extinct amphibians, reptiles (including dinosaurs and thus birds) and mammals (including primates, and all hominid subgroups including humans), as well as earlier extinct groups.https://en.wikipedia. org/wiki/Tetrapod
570TGF-beta (superfamily)A multifunctional member of the transforming growth factor superfamily. The superfamily has numerous functions in development and signaling by white blood cell lineages.https://en.wikipedia. org/wiki/ Transforming_ growth_factor_beta
571Theory of Natural SelectionTheory based on the differential survival and reproduction of individuals due to differences in phenotype. It is a key mechanism of evolution, the change due to heritable traits characteristic of a population over generations.https://en.wikipedia. org/wiki/Natural_ selection
572ThymineOne of the four nitrogenous bases found in the nucleotides of DNA.https://en.wikipedia. org/wiki/Thymine
573Tissue (biology)A cellular organizational level between cells and a complete organ. A tissue is an ensemble of similar cells and their extracellular matrix from the same origin that together carry out a specific function. Organs are then formed by the functional grouping together of multiple tissues.https://en.wikipedia. org/wiki/Tissue_ (biology)
574Toolkit (developmental or genomic)Metaphorical description of modular, reusable elements that can be modified, fine-tuned, integrated and reused, under Natural Selection.(not applicable)
575Total genomic DNAThe complete set of DNA sequences (i.e. the genome) found in the cells of a species of organism, or cells from individuals of that species.https://en.wikipedia. org/wiki/ Genomic_DNA
576Transactional interpretationTakes the psi and psi* wave functions of the standard quantum formalism to be retarded (forward in time) and advanced (backward in time) waves that form a quantum interaction as a Wheeler–Feynman handshake or transaction.https://en.wikipedia. org/wiki/ Transactional_ interpretation
577TranscriptionSynthesis of an RNA chain from a DNA template. One type of RNA gets processed during production of messenger RNA from protein-coding genes. There are several other types of RNA molecules that are also the products of transcription, including, but not restricted to, ribosomal RNAs and transfer RNAs.https://en.wikipedia. org/wiki/ Transcription_ (biology)
578Transcription factorA protein that controls the rat of transcription. Controls the rate of transcription of RNA from DNA by binding to specific DNA sequences and/or other proteins attached to a genetic locus on a chromosome.https://en.wikipedia. org/wiki/ Transcription_factor
579Transfer RNAA specialized folded RNA molecule that carries a specific amino acid to a ribosome. At the ribosome, the anticodon of the tRNA base-pairs with a complementary codon of mRNA, which places the amino acid into the correct sequence in a growing protein chain during protein synthesis (translation).https://en.wikipedia. org/wiki/Transfer_ RNA
580TranslationThe process in which ribosomes in the cytoplasm or endoplasmic reticulum synthesize proteins. This occurs after transcription of DNA and processing of messenger RNA in the cell’s nucleus.https://en.wikipedia. org/wiki/ Translation_ (biology)
581Transmembrane receptorReceptors that are embedded in the cell membrane (plasma membrane). They act in cell signaling by receiving (binding to) extracellular molecules. They are specialized integral membrane proteins that allow communication between the cell and the extracellular space. The extracellular molecules may be hormones, neurotransmitters, cytokines, growth factors, cell adhesion molecules, or nutrients; they react with the receptor to induce changes in the metabolism and activity of a cell. In the process of signal transduction, ligand binding affects a cascading chemical change through the cell membrane.https://en.wikipedia. org/wiki/Category: Transmembrane_ receptors
582Transmission (genetic)The transfer of genetic information from genes to another generation.https://en.wikipedia. org/wiki/ Transmission_ (genetics)
583Transmission electron microscopyA microscopy technique used for high magnifications that exceed the resolution of images formed by light. A beam of electrons is transmitted through a specimen to form an image. The specimen is most often an ultrathin section less than 100 nm thick or a suspension on a grid.https://en.wikipedia. org/wiki/ Transmission_ electron_microscopy
584Transposable elementA DNA sequence that can change its position within a genome. Sometimes it creates or reverses mutations and alters the cell’s genetic identity and genome size.https://en.wikipedia. org/wiki/ Transposable_ element
585Tree of life (biology)The tree of life or universal tree of life is a metaphor, model, and research tool. It is used to explore the evolution of life and describe the relationships between organisms, both living and extinct. Was described in a famous passage in Charles Darwin’s On the Origin of Species (1859).https://en.wikipedia. org/wiki/Tree_of_ life_(biology)
586Transfer RNA (tRNA)Folded, single-stranded RNA molecule with a clover-leaf shape that carries a specific amino acid to the ribosome, and base-pairs with a specific messenger RNA codon, during protein synthesis (translation).https://en.wikipedia. org/wiki/ Transfer_RNA
587UAHM (Lost City)Abbreviation for undersea alkaline hydrothermal mound. An example, called the Lost City hydrothermal field, was discovered in the Mid-Atlantic ocean.https://en.wikipedia. org/wiki/ Lost_City_ Hydrothermal_Field
588Ultramafic (rock)Igneous and meta-igneous rocks with a very low silica content. The Earth’s mantle is composed of ultramafic rocks.https://en.wikipedia. org/wiki/ Ultramafic_rock
589UltrastructureThe internal architecture of cells. It is visible at higher magnifications than found on a standard optical light microscope, such as those provided by the transmission electron microscope.https://en.wikipedia. org/wiki/ Ultrastructure
590Undersea alkaline hydrothermal mound (see alkaline hydrothermal vent)An undersea projection above the seafloor formed by the porous precipitates that form from adjacent alkaline hydrothermal vents.https://en.wikipedia. org/wiki/ Hydrothermal_vent
591Unequal crossing-overA type of crossover that results in duplication or deletion of segments of genomic DNA. A major mechanism involved in gene duplication.https://en.wikipedia. org/wiki/ Unequal_crossing_ over
592Unicellular (organism)A prokaryotic or eukaryotic organism that usually carries out its life cycle as separate individual cells.https://en.wikipedia.org/ wiki/Unicellular_ organism
593UnitAn entity that represents a cohesive whole, often composed of interacting subunits.https://en.wiktionary. org/wiki/unit
594UniverseAll of space and time and their contents, including planets, stars, galaxies, and all other forms of matter and energy.https://en.wikipedia. org/wiki/Universe
595Updated Evolutionary Synthesis (UES)A term introduced in Rethinking Evolution to describe a 21st century synthesis of evolutionary theory that recognizes the significance of Natural Selection and also several new complementary principles that are well-supported by wide-ranging empirical discoveries in molecular, cellular and developmental biology.(not applicable)
596UracilOne of the four nitrogenous bases found in nucleotides of RNA.https://en.wikipedia. org/wiki/Uracil
597UV (radiation)Electromagnetic radiation consisting of photons that have higher energy than violet colored light and fall outside of the spectrum of light visible to humans. Certain wavelengths of UV light can mutate DNA or damage proteins.https://en.wikipedia. org/wiki/Ultraviolet
598V(D)J recombinationThe unique mechanism of genetic recombination that occurs only in developing lymphocytes during the early stages of T and B cell maturation. It involves somatic recombination, and results in the highly diverse repertoire of antibodies/ immunoglobulins (Igs) and T-cell receptors (TCRs) produced by individual B cells and T cells, respectively.https://en.wikipedia. org/wiki/V(D) J_recombination
599VariationMeans that biological systems are different over space. Occurs within and among populations.https://en.wikipedia. org/wiki/ Genetic_variation
600Venting(hydrothermal, undersea)Release of geothermally heated water from an oceanic fissure in the Earth. In the context of the Origin of Life, this continuous flow can release waste products from organic chemical reactions.https://en.wikipedia. org/wiki/ Hydrothermal_vent
601VertebrateA species of animal with a backbone, classified within the vertebrate subphylum of chordates.https://en.wikipedia. org/wiki/Vertebrate
602Viable offspringOffspring that are able to survive up to reproductive age. To continue an evolutionary lineage, they must be able to breed and produce another generation of viable offspring.https://en.wikipedia. org/wiki/ Genetic_viability
603Virulent (pathogen)An adjective describing a pathogen’s or microbe’s ability to infect and/or damage an organism’s host cells.https://en.wikipedia. org/wiki/Virulence
604VirusA small infectious agent that replicates only inside living cells of other organisms. Viruses usually have a high degree of host specificity but are widespread in prokaryotes (e.g. bacteriophages) and eukaryotes (e.g. influenza, HIV, etc.).https://en.wikipedia. org/wiki/Virus
605Waste products (metabolic waste)In metabolism, refers to unwanted or unusable materials. Often, such materials are harmful to living cells and must be excreted.https://en.wikipedia. org/wiki/ Metabolic_waste
606Water moleculesMolecules consisting of two covalently bonded hydrogen atoms and one oxygen atom (H2O). Water molecules are vital for all forms of life, and are the main constituent of Earth’s streams, lakes, and oceans.https://en.wikipedia. org/wiki/Water
607Wnt (signaling pathway)A group of signal transduction pathways which begin with proteins that pass signals into a cell through cell-surface receptors. Play a variety of roles in development.https://en.wikipedia. org/wiki/ Wnt_signaling_ pathway
608Wood-Ljungdahl (acetyl-CoA) pathwayA set of biochemical reactions used by some bacteria and archaea. Enables organisms to use hydrogen as an electron donor and carbon dioxide as an electron acceptor, providing raw materials for organic biosynthesis and energy transformation.https://en.wikipedia. org/wiki/Wood% E2%80%93Ljungdahl_pathway
609X-ray diffractionA technique used for determining the atomic and molecular structure of a crystal. Can produce a 3D picture of the density of electrons within a crystal.https://en.wikipedia. org/wiki/X-ray_ crystallography
610X-raysA form of high-energy electromagnetic radiation. Can break DNA and cause mutations.https://en.wikipedia. org/wiki/X-ray
611Yin-yangDescribes how seemingly opposite or contrary forces may be complementary. Each may give rise to the other.https://en.wikipedia. org/wiki/ Yin_and_yang
612Zebrafish (Danio rerio)A freshwater fish belonging to the minnow family. The zebrafish is an important and widely used vertebrate model organism in scientific research, including developmental biology and evo-devo.https://en.wikipedia. org/wiki/Zebrafish
613ZeitgeistAn invisible agent or force dominating the characteristics of a given epoch in world history.https://en.wikipedia. org/wiki/Zeitgeist
614Zygote (fertilized egg)A fertilized egg resulting from the fusion of a sperm cell and an egg cell during sexual reproduction.https://en.wikipedia. org/wiki/Zygote

This Glossary is reprinted from “Rethinking Evolution: The Revolution That’s Hiding in Plain Sight,” copyright (c) 2019 by World Scientific Publishing Company and Gene Levinson PhD. All rights reserved. All links and excerpts derived from external public web sites, such as Wikipedia.org, are subject to the licenses, copyrights and Terms of Use of those external web sites.