| Term | Definition |
| homologous structures | Structures derived from a common ancestor or same evolutionary or developmental origin |
| nitrification | to impregnate with nitrogen or nitrogen compounds. |
| eutrophic | (of a lake) characterized by an abundant accumulation of nutrients that support a dense growth of algae and other organisms, the decay of which depletes the shallow waters of oxygen in summer. |
| use and disuse | life started out simple and became more complex & Lamarck believed that disuse would cause a trait to become reduced &He believed that traits changed or acquired over an individual's lifetime could be passed down to its offspring. |
| gene splicing | recombinant DNA technology. |
| sex influenced | traits controlled by autosome; sex influenced trait is baldness |
| nitrifying bacteria | Any of various soil bacteria that change ammonia or ammonium into nitrite or change nitrite into nitrate as part of the nitrogen cycle |
| omnivore | eating both animal and plant foods. |
| dihybrid | the offspring of parents differing in two specific pairs of genes. |
| mRNA | messenger RNA. |
| genotype | the genetic makeup of an organism or group of organisms with reference to a single trait, set of traits, or an entire complex of traits. |
| nucleotide | any of a group of molecules that, when linked together, form the building blocks of DNA or RNA: composed of a phosphate group, the bases adenine, cytosine, guanine, and thymine, and a pentose sugar, in RNA the thymine base being replaced by uracil. |
| codon | a triplet of adjacent nucleotides in the messenger RNA chain that codes for a specific amino acid in the synthesis of a protein molecule. |
| herbivore | feeding on plants. |
| carnivore | an animal that eats flesh. |
| consumer | an organism, usually an animal, that feeds on plants or other animals. |
| Recombinant DNA | DNA in which one or more segments or genes have been inserted, either naturally or by laboratory manipulation, from a different molecule or from another part of the same molecule, resulting in a new genetic combination. |
| evaporation | to change from a liquid or solid state into vapor; pass off in vapor. |
| translation | change or conversion to another form, appearance, etc.; transformation |
| subspecies | a subdivision of a species, especially a geographical or ecological subdivision. |
| sex linked | (of a gene) located in a sex chromosome. |
| population | the assemblage of a specific type of organism living in a given area. |
| species | composed of related individuals that resemble one another, are able to breed among themselves, but are not able to breed with members of another spe |
| transpiration | the passage of water through a plant from the roots through the vascular system to the atmosphere. |
| Gregor Mendel | Through the selective cross-breeding of common pea plants (Pisum sativum) over many generations, Mendel discovered that certain traits show up in offspring without any blending of parent characteristics. |
| evolution | change in the gene pool of a population from generation to generation by such processes as mutation, natural selection, and genetic drift. |
| food web | a series of organisms related by predator-prey and consumer-resource interactions; the entirety of interrelated food chains in an ecological community. |
| producer | Animals are called consumers. This is because they cannot make their own food, so they need to consume (eat) plants and/or animals. |
| heterotroph | an organism requiring organic compounds for its principal source of food |
| Darwin | proposed a theory of evolution occurring by the process of natural selection. The animals (or plants) best suited to their environment are more likely to survive and reproduce, passing on the characteristics which helped them survive to their offspring. |
| dentrification | to reduce (nitrates) to nitrites, ammonia, and free nitrogen, as in soil by microorganisms. |
| primary consumer | (in the food chain) an animal that feeds on plants; a herbivore. |
| dentrifying Bacteria | Soil microorganisms whose action results in the conversion of nitrates in soil to free atmospheric nitrogen, thus exhausting soil fertility and reducing agricultural productivity. |
| DNA | Genetics. deoxyribonucleic acid: an extremely long macromolecule |
| condensation | to become liquid or solid, as a gas or vapor |
| Lamarck | Lamarck: The theory of transformation |
| vestigial structures | Vestigial structures provide a clue to the evolutionary history of a species because they are remnants of structures found in the ancestral species. |
| dominant | the one of a pair of alternative alleles that masks the effect of the other when both are present in the same cell or organism. |
| gene pool | the total genetic information in the gametes of all the individuals in a population. |
| Restriction Enzyme | any of a group of enzymes that catalyze the cleavage of DNA molecules at specific sites: used for gene splicing in recombinant DNA technology and for chromosome mapping. |
| oligiotrophic | (of a lake) characterized by a low accumulation of dissolved nutrient salts, supporting but a sparse growth of algae and other organisms, and having a high oxygen content owing to the low organic content. |
| phenotype | the appearance of an organism resulting from the interaction of the genotype and the environment. |
| homozygous | having identical pairs of genes for any given pair of hereditary characteristics. |
| decomposer | an organism, usually a bacterium or fungus, that breaks down the cells of dead plants and animals into simpler substances. |
| carrying capacity | the maximum, equilibrium number of organisms of a particular species that can be supported indefinitely in a given environment. Abbreviation: K |
| tRNA | One of a class of RNA molecules that transports amino acids to ribosomes for incorporation into a polypeptide undergoing synthesis. Also called transfer RNA . |
| RNA | ribonucleic acid any of a class of single-stranded molecules transcribed from DNA in the cell nucleus or in the mitochondrion or chloroplast, containing along the strand a linear sequence of nucleotide bases that is complementary to the DNA strand |
| biomass | the amount of living matter in a given habitat, expressed either as the weight of organisms per unit area or as the volume of organisms per unit volume of habitat. |
| binomial nomenclature | a formal system used in biology to name organisms. |
| monohybrid | the offspring of individuals that differ with respect to a particular gene pair. |
| transcription | to make an exact copy of |
| density independent | A factor that influences individuals in a population in a manner that does not vary with the extent of crowding present in the population. |
| density dependent | Density dependence occurs when the population growth rate, or constituent gain rates (e.g. birth and immigration) or loss rates (death and emigration), vary causally with population size or density |
| Plasmid | a segment of DNA independent of the chromosomes and capable of replication, occurring in bacteria and yeast: used in recombinant DNA procedures to transfer genetic material from one cell to another. |
| heterozygous | having dissimilar pairs of genes for any hereditary characteristic. |
| mutation | a sudden departure from the parent type in one or more heritable characteristics, caused by a change in a gene or a chromosome. |
| anticodon | a sequence of three nucleotides in a region of transfer RNA that recognizes a complementary coding triplet of nucleotides in messenger RNA during translation by the ribosomes in protein biosynthesis. |
| recessive | that one of a pair of alternative alleles whose effect is masked by the activity of the second when both are present in the same cell or organism. |
| autotroph | any organism capable of self-nourishment by using inorganic materials as a source of nutrients and using photosynthesis or chemosynthesis as a source of energy, as most plants and certain bacteria and protists. |
| Linnaeus | Carl Linnaeus is often called the Father of Taxonomy. His system for naming, ranking, and classifying organisms is still in wide use today (with many changes). |
| food chain | a series of organisms interrelated in their feeding habits, the smallest being fed upon by a larger one, which in turn feeds a still larger one, etc. |
| natural selection | forms of life having traits that enable them to adapt to specific environmental pressures, as predators, changes in climate, or competition for food or mates, will tend to survive and reproduce in greater numbers than others of their kind. |
| Sticky Ends | single-stranded end of DNA or RNA having a nucleotide base sequence complementary to that of another strand, enabling the two strands to be connected by base pairing |
