Chapter 23

Question 1

Microevolution

Answer 1

Change in allele frequencies in a population over generations

Question 2

Geographic variation

Answer 2

Differences in genetic composition of separate populations

Question 3

Mechanism responsible for adaptive evolution

Answer 3

Natural selection, genetic Drift and gene flow

Question 4

Natural selection

Answer 4

The differential reproductive success of individual within a population based on how well those individuals are adapted to their environment

Question 5

Types of natural selection

Answer 5

Directional selection, disruptive selection, stabilizing selection

Question 6

Directional selection

Answer 6

Occurs when conditions favourite individual exhibiting one extreme or phenotypic range, thus shifting a populations frequency curve for a phenotypic character in One Direction or the other

Question 7

Disruptive selection

Answer 7

Occurs when conditions favor individuals have both extreme of a phenotypic range or individuals with intermediate phenotypes

Question 8

Stabilizing selection

Answer 8

Acts against both extremes phenotypes and favours intermediate variants

Question 9

Genetic drift

Answer 9

Chance events can also cause a little frequencies to fluctuate unpredictably from one generation to the next especially in small populations.

Founder effect: few indivdl’s become isolated from larger pop’n
Bottleneck effect: severe drop in pop’n size

Question 10

Gene flow

Answer 10

Transfer of alleles into or out of the population due to movement of fertile individuals or their gametes

Question 11

Geographic variation

Answer 11

Different genetic in the composition of separate population

Question 12

Mutation

Answer 12

Change in the nucleotide of the genetic material of an organism

Question 13

Population

Answer 13

Group of individuals of the same species that live in the same area and interbreed, producing fertile offspring

Question 14

Gene pool

Answer 14

Consist of all copies of every type of allele at every locus in all members of the population

Question 15

5 conditions to Hardy-Weinberg

Answer 15

Population must be very large
No mutations
No natural selection
No gene flow
Random mating

Question 16

Sexual selection

Answer 16

A form of selection in which individuals with certain inherited characteristics are more likely than other individuals to obtain mates