Ch 23

Question 1

microevolution

Answer 1

change in allele frequencies in a pop over genrations, isevolution at its smallest scale

Question 2

3 mechanism cause allele frequency change:

Answer 2

1. Natural selection (adaptation to the environment)
2. Genetic drift (chance events alter allele frequencies)
3. gene flow (transfer of alleles btw pop)

Question 3

genetic variation

Answer 3

refers to the differences in genes or other DNA sequences among individuals

Question 4

population

Answer 4

group of individuals of the same species that live in the same area & interbreed

Question 5

gene pool

Answer 5

consists of all copies of every allele at every locus in all members of the pop

Question 6

How to calculate genotype frequencies?

Answer 6

divide # of individuals of e/ genotype by total # of individuals in pop

Question 7

conditions for Hardy-Weinberg Equilibrium

Answer 7

1. no mutations
2. random mating
3. no natural selection
4. extremely large populations size
5. no gene flow

Question 8

3 major factors altering allele frequencies and bring evolutionary change

Answer 8

natural selection, genetic drift, gene flow

Question 9

adaptive evolution

Answer 9

process in which traits enhance survival or reproduction inc in frequency over time

Question 10

genetic drift

Answer 10

process in which chance events cause allele frequencies to fluctuate unpreditably from one generation to the next

Question 11

founder effect

Answer 11

occurs when a few indivudals become isolated from a larger pop

Question 12

bottleneck effect

Answer 12

occurs when there is a drastic reduction in pop size due to a sudden change in environment

Question 13

genetic drift summary

Answer 13

1. significant in small populations
2. cause allele frequencies to change at random
3. lead to loss of genetic variation w/i pop
4. cause harmful alleles to become fixed