Extra Study CH. 23 (The evolution of populations)

Question 1

What mechanisms can cause the evolution of populations?

Answer 1

Natural selection, genetic drift and gene flow

Question 2

differences among individuals in the composition of their genes or other DNA sequences

Answer 2

genetic variation

Question 3

sources of genetic variation

Answer 3

formation of new alleles (mutations), altering gene number or position, rapid reproduction and sexual reproduction

Question 4

differences in DNA sequence that do not confer a selective advantage or disadvantage

Answer 4

neutral variation

Question 5

a group of individuals of the same species that live in the same area and interbreed to produce fertile offspring

Answer 5

population

Question 6

traits that enhance survival or reproduction tend to increase in frequency over time

Answer 6

adaptive evolution

Question 7

effects of genetic drift

Answer 7

-significant in small populations
-causes allele frequencies to change at random
-can lead to a loss of genetic variation within populations
-can cause harmful alleles to become fixed

Question 8

the transfer of alleles in or out of a population due to the movement of fertile individuals and their gametes

Answer 8

gene flow