Biology Midterm Vocabulary Essay

Evolution: descent with modification; the idea that living species are descendants of ancestral species that were different from the present-day ones. Biology: the scientific study of life. Emergent properties: new properties that emerge with each step upward in the hierarchy of life, owing to the arrangement and interaction of parts as complexity increases. Systems biology: an approach to studying biology that aims to model the dynamic behavior of whole biological systems based on a study of the interactions among the systems parts.

Global climate change: increase in temperature and hangs in weather patterns all around the planet, due mostly to increasing atmospheric CO levels from the burning of fossil fuels. Eukaryotic cell: a type of cell with a membrane-enclosed nucleus and membrane-enclosed organelles. Prokaryotic cell: a type of cell lacking a membrane-enclosed nucleus and membrane-enclosed organelles. DNA: a double-stranded, helical nucleic acid molecule, consisting of nucleotide monomers with a didgeridoos sugar and the nitrogenous bases adenine (A), cytosine (C), guanine (G) and thymine (T).

Genes: a discrete unit of hereditary information consisting of a specific nucleotide sequence DNA (or RNA in some Gene expression: the process by which information encoded in DNA viruses). Directs the synthesis of proteins or, in some cases, RNA that are not translated into proteins and instead function as RNA. Genome: the genetic material of an organism or virus. Genomics: the study of whole sets of genes and their interactions within a species, as well as genome comparisons between species.

Bioinformatics: the use of computers, software and mathematical models to process and integrate biological information from large data sets. Negative feedback: a form of regulation in which the accumulation of an end product of a process slows the process. Positive feedback: a form of regulation in which the accumulation of an end product of a process speeds up the process. Bacteria: one of two prokaryotic domains, the other being Arched. Arched: one of two prokaryotic domains, the other being Bacteria. Eukaryote: the domain that includes all eukaryotic organisms.

Natural selection: a process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits. Evolutionary adaptation (peg. 17): bats, the only mammals capable of active flight, have wings with webbing between extended “fingers. ” In the Darwinian view of life, such adaptations are refined over time by natural selection. Fossils: a preserved remnant or impression of an organism that lived in the past. Strata: a rock layer formed when new layers of sediment cover older ones and compress them.

Paleontology: the study of human origins and evolution. Catastrophic: the principle that events in the past occurred suddenly and were caused by different mechanisms than those operating today. Unfamiliarity’s: the principle that mechanisms of change are constant overtime. Conservation biology: he integrated study of ecology, evolutionary biology, physiology, molecular biology and genetics to sustain biological diversity at all levels. Extirpation: the local extinction tot a species in a certain geographical area. Extinct: raters too species that is no longer found alive and has “died out”.

Endangered: a species that is in danger of extinction throughout all or a significant portion of its range. Threatened: a species that is considered likely to become endangered in the foreseeable future. Ecosystem services: a function performed by an ecosystem that directly or indirectly benefits humans. Introduced species: a species moved by humans, either intentionally or accidentally, from its native location to a new geographic region. Adaptations: inherited characteristics of an organism that enhances its survival and reproduction in a specific environment.

Artificial selection: the selective breeding of domesticated plants and animals to encourage the occurrence of desirable traits. Darning’s observation #1 : members of a population often vary in their inherited traits. Observation #2: all species can produce more offspring than their environments can support and many of these offspring fail to reproduce. Inference #1: individuals whose inherited traits give them a higher probability of surviving and reproducing in a given environment tend to leave more offspring than other individuals.

Inference #2: this unequal ability of individuals to survive and reproduce will lead to the accumulation of favorable traits in the population over generations. Homology: similarity in shared characteristics resulting from a shared ancestry. Homologous structures: structures in different species that are similar because of common ancestry. Vestigial structures: a feature of an organism that is a historical remnant of structure that served a function in the organisms ancestors. Evolutionary tree: a branching diagram that reflects a hypothesis about evolutionary relationships among groups of organisms.

Convergent evolution: the evolution of similar features in independent evolutionary lineages. Analogous: having characteristics that are similar because of convergent evolution, not homology. Biography: the study of the past and present geographic distribution of species. Pangaea: the superscription that was formed near the end of the Paleozoic era, when plate movements brought all the landmasses of Earth together. Microinstruction: evolutionary change below the species level; change in the allele frequencies in a population over generations.

Genetic variation: differences among individuals in the composition of their genes or other DNA segments. Average heterozygous: the percentage, on average, of a populations loci that are heterozygous in members of the population. Geographic variation: differences between the gene pools of geographically separate populations or population subgroups. Cline: a graded change in character along a geographic axis. Population: a group of individuals of the same species that live in the same area ND interbreed, producing fertile offspring.

Gene pool: the aggregate of all copies of every type of allele at all loci in every individual in a population. The Hardy-Weinberg Principle: 1 . No mutations: the gene pool is modified if mutations alter alleles or if entire genes are deleted or duplicated. 2. Random mating: if individuals mate preferentially within a subset of the population, such as their close relatives (inbreeding), random mixing of gametes does not occur, and genotype frequencies change. 3. No natural selection: differences in the survival and reproductive of individuals carrying efferent genotypes can alter allele frequencies. . Extremely large population size: the smaller the population, the more likely it is that the allele frequencies will delectate by chance trot one generation to the next (a process called genetic drift) 5 No gene flow: by moving alleles into or out of populations, gene flow can alter allele frequencies. Founder effect: genetic drift that occurs when a few individuals become isolated from a larger population and form a new population whose gene pool composition is not reflective of that of the original population.

Bottleneck effect: emetic drift that occurs when the size of a population is reduced, as by a natural disaster or human activities. Genetic drift (peg. 512): a process in which chance events cause unpredictable fluctuations in allele frequencies from one generation to the next. Gene flow: the transfer of alleles from one population to another, resulting from the movement of fertile individuals or their gametes. Relative fitness: the contribution an individual makes to the gene pool, of the next generation, relative to the contributions of other individuals in the population.

Directional selection: trial selection in which individuals at one end of the phenotypes range survive or reproduce more successfully than do other individuals. Disruptive selection: natural selection in which individuals on both extremes of a phenotypes range survive or reproduce more successfully than do individuals with intermediate phenotypes. Stabilizing selection: natural selection in which intermediate phenotypes survive or reproduce more successfully than do extreme phenotypes. Sexual selection: a form of selection in which individuals with certain inherited characteristics are more likely Han other individuals to obtain mates.

Sexual dimorphism: differences between the secondary sex characteristics of males and females. Interstitial selection: selection in which there is direct competition among individuals of one sex for mates of the opposite sex. Internal selection: selection whereby individuals of one sex (usually females) are choosy in selecting their mates from individuals of the other sex. Neutral variation: genetic variation that does not provide a selective advantage or disadvantage. Balancing selection: natural selection that maintains two or more phenotypes forms in a population.

Heterozygous advantage: greater reproductive success of heterozygous individuals compared with homozygous. Frequency dependent selection: selection in which the fitness of a phenotype depends on how common the phenotype is in the population. Evolutionary compromise (peg. 519): the loud call that enables a Tundra frog to attract mates also attracts more dangerous characters in the neighborhood-in this case, a bat about to seize a meal. Speciation: an evolutionary process in which one species splits into two or more species.

Macromolecular: evolutionary change above the species level. Biological species incept: definition of a species as a group of populations whose members have the potential to interbreed in nature and produce viable, fertile offspring, but do not produce viable, fertile offspring with members of other such groups. Species: a population or group of populations whose members have the potential to interbreed in nature and produce viable, fertile offspring, but do not produce viable, fertile offspring with members of other such groups.

Reproductive isolation: the existence of biological factors (barriers) that impede members of two species from producing viable, fertile offspring. Hybrids: offspring that results from the mating of individuals from two different species or from two true-breeding varieties of the same species. Precocity barriers: a reproductive barrier that impedes mating between species or hinders fertilization if interspecies mating is attempted. Posthypnotic barriers: a reproductive barrier that prevents hybrid zygotes produced by two deterrent species from developing into viable, fertile adults.

Morphological species concept: a definition of species in terms of measurable anatomical criteria. Ecological species concept: a definition of species in terms of ecological niche, the sum of how members f the species interact with the nonliving and living parts of their environment. Phylogeny species concept: a definition of species as the smallest group of individuals that share a common ancestor, forming one branch of the tree of life. Allophonic speciation: the formation of new species in populations that are geographically isolated from one another.

Symmetric speciation: the formation of new species in populations that live in the same geographic area. Polyploidy: a chromosomal alteration in which the organism possesses more than two complete chromosome sets. Autopilots: an individual that has more than two chromosome test that are all derived from a single species. Leopoldville: a fertile individual that has more than two chromosome sets as a result of two different species interbreeding and combining their chromosomes.

Hybrid zone: a geographic region in which members of different species meet and mate, producing at least some offspring of mixed ancestry. Reinforcement: in evolutionary biology, a process in which natural selection strengthens precocity barriers to reproduction, thus reducing the chances of hybrid formation. Punctuated equilibrium: in the fossil record, long periods of apparent stasis, in which a species undergoes little or no rapscallion change, interrupted by relatively brief periods of sudden change. Endemic: referring to a species that is confined to a specific geographic area.

Morphological characteristics (peg. 574): is a branch of biology dealing with the study of the form and structure of organisms and their specific structural features. Archbishopric: the arousal Claude. Molecular characteristics: (peg. 575). Phylogeny: the evolutionary history of a species or group of related species. Evolutionary trees: a branching diagram that reflects a hypothesis about evolutionary relationships among groups of organisms. Systematic: a scientific discipline focused on classifying organisms and determining their evolutionary relationships.

Binomial: the two-part, Latinized format for naming a species, consisting of the genus and specific epithet. Genus: a taxonomic category above the species level, designated by the first word of a species’ two-part scientific name. Taxonomy: a named taxonomic unit at any given level of classification. Phylogeny tree: a branching diagram that represents a hypothesis about the evolutionary history of a group of organisms. Phylogeny: proposed system of classification of organisms based on evolutionary relationships: only groups that include a common ancestor and all of its descendants are named.

Branch points: the representation on a phylogeny tree of the divergence of two or more tax from a common ancestor. Sister tax: groups of organisms that share an immediate common ancestor and hence are each other’s closest relatives. Rooted: describing a phylogeny tree that contains a branch point (often, the one farthest to the left) representing the most recent common ancestor of all tax in the tree. Basal taxonomy: in a specified group of organisms, a taxonomy whose evolutionary lineage diverged early in the history of the group.

Polyglot: in a phylogeny tree, a branch point from which more than two descendant taxonomy emerge. A polyglot indicates that the evolutionary relationships between the descendant tax are not yet clear. Analogy: similarity between two species that is due to convergent evolution rather than to decent from a common ancestor with the same trait. Homeostasis: a similar (analogous) structure or molecular sequence that has evolved independently in two species. Molecular systematic: a scientific discipline that uses nucleic acids or other molecules to infer evolutionary relationships between different species.

Classicist: an approach to systematic in which organisms are placed into groups called classes based primarily on common descent. Monopolistic: pertaining to a group of tax that consists of a common ancestor and all of its descendants. A monopolistic taxonomy is equivalent to a Claude. Paralytic: pertaining to a group of tax that consists of a common ancestor and some, but not all, of its descendants Polytechnic: pertaining to a group of tax derived from two or more different ancestors. Shared ancestral character: a character, shared by particular members of a Claude that originated in an ancestor which is not a member of that Claude.

Shared derived character: an evolutionary novelty that is unique to a particular Claude. Outgrip: a species or group of species from an evolutionary lineage that is known to have diverged before the lineage that contains the group being studied. Ingrown: a species or group of species whose evolutionary relationships we seek to determine. Clamored: a branching diagram that is used to show phylogeny relationships among organisms. Phylogeny: a phylogeny tree wherein the branch lengths are proportional to the amount of change seen in species’ characteristics.

Orthogonal genes: homologous genes that are found in different species because of speciation. Parlous genes: homologous genes that are found in the same genome as a result of gene duplication. Molecular clock: a method for estimating the time required for a given amount of evolutionary change, based on the observation that some regions of genomes evolve at constant rates. Horizontal gene transfer: the transfer of genes from one genome to another through mechanisms such as transposable elements, plasmid exchange, viral activity and perhaps fusions of different organisms.