Chapter 23

Question 1

population genetics

Answer 1

study of genes + genotypes in a population
based on changes in the gene pool

Question 2

gene pool

Answer 2

all alleles for every gene in the population
(can also be described

Question 3

population

Answer 3

all the species in a pre-defined location

Question 4

polymorphisms

Answer 4

having 2 or more versions of a trait in a population

Question 5

monomorphic

Answer 5

only 1 trait

think teeth, etc

Question 6

what can be mutated?

Answer 6

genone > chromosome > gene > base pair
most common mutation is SNPs

Question 7

SNP

Single Neuleotide Polymorphism

Answer 7

a base pair change, accounts for 90% of all variation among humans

Question 8

allele frequency

Answer 8

= # of specific allele/total # of alleles

if frequencies change, evolution is happening

Question 9

genotype frequency

Answer 9

= # of specific genotype/# of all genotypes

if frequencies change, evolution is happening

Question 10

punnett square

Answer 10

used to calculate what alleles, genotypes, and phenotypes we should get in the next generation

Question 11

equillibrium

Answer 11

allele and genotype frequencies do not change from generation to generation

Question 12

evolution

Answer 12

changes in genotypes over time in populations

Question 13

Hardy Weinberg Equilibrium

Answer 13

p + q = 1
p² + 2pq + q² = 1

Question 14

selection

Answer 14

differences in survival + reproduction between individuals exhibiting different phenotype

Question 15

directional selection

Answer 15

changes the average value of a trait by selecting for one extreme
(slightly reduces overall population variation)

Question 16

stabilizing selection

Answer 16

can change the average value of a trait by selecting for intermediate values
(greatly reduces overall variation)

Question 17

disruptive selection

Answer 17

maintains the average value of a trait by selecting for both extremes
(greatly increases overall variation but doesnt affect the average)

Question 18

balancing selection

Answer 18

2 or more alleles maintained in a population over time

Question 19

artificial selection

aka selective breeding

Answer 19

the process of modifying organisms by selection in breeding controlled by humans

Question 20

sexual selection

Answer 20

type of natural selection on traits that are directly involved with reproduction
*males with the “best” traits will reproduce more & pass traits on

Question 21

natural selection will create differences:

Answer 21

1. within species (microevolution)
2. among species (maco-)
3. between or within sexes within a species

Question 22

intrasexual selection

Answer 22

male to male competition

Question 23

intersexual selection

Answer 23

male to female competition

(when female is present, female choice)

Question 24

genetic drift

Answer 24

change in allele freq. in adaptation due to chance variation in the survival + reproduction of individuals

(if its random, then its not adaptive)

Question 25

founder effect

Answer 25

change in allele freq. due to genetic drift resulting from random saompling effects.

when a small # of “founder individuals” colonize a new area

Question 26

bottleneck effect

Answer 26

event where population drastically reduces, increases likelihood that rare genes are lost

Question 27

migration

Answer 27

the movement of alleles between populations (gene flow)

(doesnt require movement: trees, pollen)

Question 28

non-random mating

Answer 28

not all individuals have an equal chance of reproducing; mating that has not occured due to chance

Question 29

factors that contribute to non-random mating

Answer 29

1. geography
2. mate choice by phenotype
3. mate choice genetic history (inbreeding)

Question 30

inbreeding

Answer 30

more likely to occur when population is small

Question 31

selfing

Answer 31

results in excess homozygosity (self fertilizing)

(most extreme form of inbreeding)

Question 32

inbreeding depression

Answer 32

decrease in fitness due to lost of heterozygosity