Campbell Biology: chapter 23 Flashcards


Set Details Share
created 10 years ago by felchuk13
1,257 views
book cover
Campbell Biology
No Chapter
the evolution of populations
updated 10 years ago by felchuk13
Grade levels:
12th grade
Subjects:
ap bio, science, life sciences, biology
show moreless
Page to share:
Embed this setcancel
COPY
code changes based on your size selection
Size:
X
Show:

1

________ evolve while _______ do not.

populations; individuals

2

Change in allele frequencies in a population over generations

microevolution

3

What are the three min mechanisms that can cause allele frequency change?

Natural selection, genetic drift, gene flow

4

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

genetic variation

5

The average percentage of loci that are heterozygous

average hetrozygosity

6

differences in the genetic compositions of separate populations

geographic variation

7

a graded change in character along a geographic axis

cline

8

Consists of all copies of every type of allele at every locus in all members of its population

gene pool

9

If only one allele exists for a particular locus in a population, that allele is said to be ____.

fixed

10

States that the frequencies of alleles and genotypes in a population will remain constant from generation to generation.

hardy Weinberg principal

11

what are the 5 hardy Weinberg conditions?

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

12

Chance events that can cause allele frequencies to fluctuate unpredictably from one generation to the next .

genetic drift

13

What are two examples of circumstances that can result n genetic drift?

fonder effect and bottle neck effect

14

When few individuals become isolated from larger population, this smaller group my establish a new population whose gene pool differs from the source population

founder effect

15

Sudden change in the environment, such a fire or flood, may drastically reduce the size of a population.

bottleneck effect

16

the transfer of alleles into or out of a population due to the movement of fertile individuals or their gametes.

gene flow

17

the contribution an individual makes to the gene pool of the next generation relative to the contributions of other individuals

relative fitness

18

occurs when conditions favor individuals exhibiting one extreme of a phenotypic range, thereby shifting a populations frequency curve for the phenotype character in one direction or the other.

directional selection

19

occurs when conditions favor individuals at both extremes of a phenotypic range over individuals with intermediate phenotypes.

disruptive selection

20

acts against both extreme phenotypes and favors intermediate variants.

stabilizing selection

21

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

sexual selection

22

What can sexual selection result in?

sexual dimorphism

23

Difference between the two sexes in secondary sexual characteristics

sexual dimorphism

24

meaning selection within the same sex, individuals of one sex compete directly for mates of the opposite sex.

intrasexual

25

mate choice- individuals of one sex are choosy in selecting their mates from the other sex.

intersexual

26

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

neutral variation

27

occurs when natural selection maintains two or more forms in a population

balancing selection

28

if individuals who are heterozygous at a particular locus have greater fitness than do both kinds of homozygous

heterozygote advantage

29

the fitness of a phenotype depends on how common it is in the population

frequency-dependent selection