Chapter 23 Flashcards Preview

Bio > Chapter 23 > Flashcards

Flashcards in Chapter 23 Deck (29):
0

During the drought of Daqhne Major, did the beak of any individual finch get larger?

No

1

Evolution on its smallest scale
Change in allele frequencies in a population over generations

Microevolution

2

Name a heritable trait

Height

3

Are all individuals in a population identical with respect to a heritable trait?

No

4

Differences in a population
Provides the raw material for evolution

Genetic variation

5

Name a phenotype that is not heritable

Big muscles

6

Would you expect two populations of the same species in different locations to have identical genetic compositions?

No

7

A gradual change in genetic composition along a geographic gradient is called a

Cline

8

New alleles arise through the process of

Mutation

9

Genetic variation can also arise through errors __ genes or ___ them around

Duplicate, move

10

Most of the time, changes to genes is

Harmful

11

What population would accumulate the most mutations in a year

Virus

12

Genetic variation is also increased through

Sexual reproduction

13

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

Population

14

When a population has only one allele for a particular locus, that allele is considered to be __ in the gene pool of that population

Fixed

15

Imagine a population of wildflowers with 500 individuals. There are 20 plants with red flowers, 160 with pink flowers, and 320 with white flowers. What is the percent of the Cr allele? And Cw?

20% and 80%

16

The Hardy-Weinberg principle applies to populations that __ evolving with respect to that particular trait

Are not

17

If you know the proportion of two alleles in a population, you can predict the frequency of each of the three possible genotype a by using the

Multiplication rule

18

What is the formula for the Hardy-Weinberg equation?

P2 + 2pq + q2 = 1

19

What are the 5 assumptions that must be met for the population to be considered to be in a Hardy-Weinberg equilibrium?

No mutations
Random mating
No natural selection
Extremely large population size
No gene flow

20

When there is selection against both extremes and in favor of the intermediate phenotype

Stabilizing selection

21

When both extremes are favored over the intermediate phenotype

Disruptive selection

22

When selection favors one extreme phenotype over the other

Directional selection

23

Which selection affected the soapberry bug?

Directional

24

Two ways in which mating is not random?

Only mating with a spouse
An individual preferring a certain phenotype and mating with individuals with the phenotype

25

In diploid organisms __ alleles can be maintained over time even if they are harmful, because they are preserved in heterozygous individuals

Recessive

26

How does sickle cell disease relate to heterozygous advantage?

Those with the heterozygote for sickle cell have protections against malaria

27

Many predators form a "search image", which allows them to spot prey more easily. Typically, they will match this search image to whatever color of prey is most abundant. Therefore, prey with the most common color are more likely to get eaten. This results in

Frequency selection

28

Three reasons why natural selection doesn't create perfect organisms

Selection can only act on existing variation
Evolution is limited by historical constraints
Adaptions are often comrpomises