Chap 21

Question 1

what evolves?

Answer 1

people don’t evolve, populations evolve

Question 2

population

Answer 2

a group of individuals of the same species that live and interbreed in a particular geographic area.

Question 3

adaptation

Answer 3

processes by which useful characteristics evolve and the characteristics themselves.

Question 4

a heritable trait is partly determined by

Answer 4

a gene

Question 5

allele

Answer 5

different forms of genes

Question 6

gene pool

Answer 6

where the sum of all copies of all alleles at which loci found in population consist

Question 7

5 forces of evolution

Answer 7

1. mutation
2. genetic drift
3. gene flow
4. non random mating
5. natural selection

Question 8

mutation

Answer 8

change in the nucleotide sequence of an organisms DNA

Question 9

gene drift

Answer 9

random changes in allele frequencies from one generation to the next. change based on chance (environmental events)

Question 10

gene flow

Answer 10

can change alelle frequencies in population. Transfer of alleles from one population to another. May add new alleles to population

Question 11

non random mating

Answer 11

mates are chosen on phenotype to ensure a good set of genes is passed on

Question 12

natural selection

Answer 12

favorable traits become more common and unfavorable traits become less common.

Question 13

stabilizing selction

Answer 13

preserves the average characteristics of a population by favoring average individuals

Question 14

directional selection

Answer 14

changes the characteristics of a population by favoring individuals that vary in one direction from the mean of the population

Question 15

disruptive selection

Answer 15

individuals at opposite extremes of a character distribution contribute more offspring to the next generation than individuals close to the mean

Question 16

Hardy Weinburg equillibrium

Answer 16

allele frequencies do not change. certain conditions are met, genetic structure of a population does not change over time