AP Bio: Unit 7

adaptation

trait that helps an organism survive/reproduce

selective breeding

when organisms are bred to result in a specific trait

result of selective breeding

produces varieties in species with desired traits

another name for selective breeding

artificial selection

natural selection was developed by…

Charles Darwin, Alfred Russel Wallace

individuals are …

selected

populations…

evolve

selective pressure

environmental factors that favor certain traits or phenotypes over others, ultimately driving the evolution of a species.

sexual dimorphism

when male and females of the same species appear different

sexual selection

when an organisms physical characteristics impact its ability to mate and reproduce

intersexual selection

members of one sex select a member of the other sex

intrasexual selection

competition between the same sex to win the over the other sex

gene pool

total amount of alleles in a population

fixed alleles

genes with only one type of allele in a population

allele frequency

how often an allele appears in a gene pool

population genetics

study of how genes are distributed in a ppoulation

Hardy Weinberg equilibrium

principle in evolution that describes the non-evolving allele and genotype frequencies over multiple generations

p + q = 1

frequency of individual alleles in a population

p² + 2pq +q² = 1

frequency of homozygous dominant and recessive and heterozygous alleles.

five conditions needed for genetic equilibrium

1. population must be large

2. population must be isolated

3. no mutation

4. mating is random

5. no increase in harmful or beneficial alleles

gene flow

transfer of genes from one population to another

assortative mating

mating pattern where organisms mate with organisms with a similar phenotype

directional selection

type of selection that leans towards a specifc phenotype

stabilizing selection

highest amount of alleles are present at the mean phenotypes/genotypes, not one extreme or the other

disruptive selection

where both extremes are more common in a population

genetic drift

a change in allele frequencies caused by the random selection and reproduction of alleles

founder effect

when certain individuals leave and start a new population, reducing genetic diversity

bottleneck effect

when an event causes sudden drop off of a population, creating a bottleneck shape.

descent with modification

darwinds summary for evolution, a species’s descendants will change over time

antibiotic

drug that kills bacteria

bacterial strain

subtype of bacteria with a genetically unique makeup

Antibiotic-resistant bacteria strains

bacterial strains that have evolved to be resistant to bacteria

adaptive radiation

when a lineage splits into multiple branches, resulting in several descendants.

homologous structures

structures that are similar that come from a similar anscestor

vestigal trait/structure

a structure that has lost its function and only remains in a reduced form.

the fossil record

history of life documented through fossils

superposition

method of relative dating fossils by assuming the outer most layers of rock are younger

index fossils

fossils that are recognized to signify a specific time period

radiometric dating

definate method of dating done by determining the half life of radioactive isotopes and radioactive decay

transitional fossils

fossils that contain features that are similar to both an ancestral group and its descendants.

biogeography

geographic distribution of species

convergent evolution

process where separate selective pressures result in similar looking adaptations that are unrelated to a common ancestor.

analogous structures

structures that appear similar but are NOT the result of a common ancestor

features that all eukaryotes share

1. Mitochondria

2. Complex cells with internal compartments such as the rough and smooth endoplasmic reticulum, the Golgi apparatus, and lysosomes.

3. A membrane-bound nucleus encloses the cell’s chromosomes, separating the chromosomes from the cytoplasm.

4. Linear chromosomes (as opposed to the circular chromosomes in bacteria and archaea).

genus

first part of a species name

specific epithet

second part of a species name

binomial nomaclature

scientific naming system wiht two parts

categories by which wer catergorize species