Chapter 16 (HALF OF FINAL)

Question 1

population

Answer 1

defined as a group of organisms of a single species living together in the same geographic area

Question 2

microevolution

Answer 2

pertains to evolutionary change within populations

Question 3

population genetics

Answer 3

the field of biology that studies the diversity of populations at the level of the gene

Question 4

gene pool

Answer 4

the alleles of all genes in all individuals in a population

Question 5

Yuh

Answer 5

Yuh

Question 6

allele frequency

Answer 6

the percentage of each allele in a population’s gene pool

Question 7

Hardy-Weinberg equilibrium

Answer 7

a stable, non-evolving state. aka genetic equilibrium. a population in which allele frequencies do not change over time.

Question 8

hardy-weinberg principle

Answer 8

proposes that the genotype frequencies of a nonevolving population can be described by the expression p^2 + 2pq + q^2, again with p and q representing the frequency of alleles D and d.

Question 9

hardy-weinberg principle only applies…

Answer 9

no mutation, no migration, large gene pool, random mating, no selection

Question 10

gene flow

Answer 10

the movement of alleles between populations. occurs when plants/animals migrate, or more specifically their gametes move between populations.

Question 11

genetic drift

Answer 11

refers to changes in the allele frequencies of a gene pool due to chance events. such events remove individuals and their genes from a population at random, without regard for genotype or phenotype

Question 12

bottleneck effect

Answer 12

a type of genetic drift in which the loss of genetic diversity is due to natural disasters, disease, overhunting, overharvesting, or habitat loss

Question 13

founder effect

Answer 13

another type of genetic drift, is similar to bottleneck effect except that genetic variation is lost when a few individuals break away from a large population to found a new population

Question 14

inbreeding

Answer 14

mating between relatives, a by-product of a very small population is a higher-than-normal occurrence of inbreeding.

Question 15

nonrandom mating

Answer 15

this alone does not cause allele frequencies to change. however, does affect how the alleles in the gene pool assort into genotypes, thus affecting the phenotypes in a population

Question 16

assortative mating

Answer 16

occurs when individuals choose a mate with a preferred trait, such as a particular coat color, feather length, or body size

Question 17

natural selection

Answer 17

in nature some phenotypes do have a reproductive advantage. over time, selection for this advantageous trait increases the frequency of the alleles associated with it, while other alleles decrease. the foundation of darwin’s theory of evolution

Question 18

polygenic traits

Answer 18

traits controlled by multiple genes

Question 19

types of natural selection

Answer 19

stabilizing, directional, and disruptive

Question 20

stabilizing selection

Answer 20

occurs when an intermediate phenotype is the most adaptive for the given environmental conditions (ex: human birth weight)

Question 21

directional selection

Answer 21

occurs when an extreme phenotype is favored, and the distribution curve shifts towards one of the extremes (ex: changes of bacterial population)

Question 22

disruptive selection

Answer 22

found when 2+ extreme phenotypes are favored over the intermediate phenotype (ex: british land snails have a wide habitat range that includes low vegetation areas and forests)

Question 23

sexual selection

Answer 23

refers to adaptive changes in males and females that lead to an increased ability to secure a mate

Question 24

fitness

Answer 24

the ability to produce surviving offspring

Question 25

female choice

Answer 25

good genes hypothesis: females choose mates on the basis of traits that improve the chance of survival

runaway hypothesis: females choose mates on the basis of traits that improve male appearance

Question 26

sexual dimorphism

Answer 26

meaning that males and females differ in size and other traits

Question 27

cost-benefit analyses

Answer 27

have been done to determine whether the benefit of access to mating is worth the cost of competition among males

Question 28

dominance hierarchies

Answer 28

males and females have separate dominance hierarchies, in which a higher-ranking animal has greater access to resources than does a lower-ranking animal

Question 29

territory

Answer 29

an area that is defended against competitors

Question 30

territoriality

Answer 30

includes the type of defensive behavior needed to defend a territory

Question 31

heterozygote advantage

Answer 31

occurs when the heterozygote is favored over the two homozygotes (ex: heterozygous individuals don’t die from sickle cell disease or malaria)