Chapter 7

Question 1

Should see 3:1 brachydactylous:wild type in population
Dominant will be selectively advantageous
Or at least take over

Answer 1

incorrect beliefs

Question 2

relative commonness or rarity of alleles

Answer 2

allele frequency

Question 3

genetic variation in sexually reproducing species

Answer 3

recombination into heterozygotes or homozygotes

Question 4

Depends on relative abundances of alleles

Answer 4

Genetic Variation

Question 5

Alterations in gene frequencies in one generation

Answer 5

Genetic Variation

Question 6

Will alter the alleles carried to next generation

Answer 6

Genetic Variation

Question 7

When genotypes have predicted frequencies

Answer 7

Hardy-Weinberg Equilibrium

Question 8

Was the original population in H-W quilibrium

Answer 8

Chi Square

Question 9

Genotype frequencies obtain H-W values after how many rounds of random mating

Answer 9

one

Question 10

If something caused a population to not be in equilibrium

Answer 10

One round of random mating would obscure that

Question 11

Allele frequencies don’t change from one generation to the next so a new mutation would remain rare

Answer 11

true

Question 12

is when populations violate the assumptions of H-W

Answer 12

Evolution

Question 13

H-W assumptions

Answer 13

1. No natural selection- all individuals have equal chances at survival and reproduction.
2. Mating is random- no sexual selection
3. No migration
4. The population is effectively infinite (no changes by chance alone) - No Genetic drift - random change in small populations

Question 14

a value for how much survival is decreased for a particular phenotype
s

Answer 14

Need Selection Coefficient

Question 15

The larger the selection coefficient is, the stronger the…

Answer 15

action of natural selection \

-so when s is a bigger number, the A1 allele approaches fixation earlier.

Question 16

An allele is consistently favored

Answer 16

Directional Selection

Question 17

Will lead to fixation – will be only allele in population (well, just about at least).

Answer 17

Directional Selection

Question 18

Rate differs whether allele is dominant or recessive

-recessive is slower to reach fixation

Answer 18

Directional Selection

Question 19

Why is directional selection slow when recessive gene is expressed?

Answer 19

• Most A1 are in heterozygotes and phenotype not expressed

- Slow to build up more successful homozygotes

Question 20

In directional selections this reaches fixation faster

Answer 20

Codominant

Question 21

In directional selections this receives some advantage from the A1 allele

Answer 21

Heterozygotes

Question 22

In directional selections this reaches fixation slower

Answer 22

Dominant A1

Question 23

In directional selections this is hard to remove from a population

Answer 23

A2

Question 24

-If A1 is rare, there will be an increase in the gene

I-f it is common, there will be a decrease because more, less fit homozygotes

Answer 24

overdominance

Question 25

a stable polymorphism

Answer 25

Balancing selection- this is very rare

Question 26

Sickle-cell (S allele vs. A) AS suffer slight anemia, SS severe anemia But normal, AA, have higher mortality from malaria Blood cells of heterozygotes broken down more rapidly limiting chance of survival

Answer 26

example of overdominance

Question 27

Heterozygote has lower fitness

Answer 27

Underdominance

Question 28

If an allele is rare, it will be lost because most are in heterozygotes RARER

Answer 28

Underdominance

Question 29

Diversifying Selection

Answer 29

Underdominance

Question 30

Black-bellied seedcrackers - bimodal distribution of bill depth Probably not one gene

Answer 30

Diversifying Selection

Question 31

Heterozygotes have severe autoimmune disease

Answer 31

Underdominance

Question 32

Costs and benefits of a trait depend on how many individuals with such a trait are present in the population

Answer 32

Frequency Dependent Selection

Question 33

fitness increases as number of individuals with the trait increase in population.

Answer 33

Positive Frequency Dependent Selection

Question 34

Flat Land Snails – mate face to face Can only mate with snails whose shells coil in same direction Higher the frequency of either type, the greater the success

Answer 34

Positive Frequency Dependent Selection

Question 35

Fitness of a trait decreases as frequency of the trait increases Scale-eating cichlid Perissodus microlepis attacks from behind Right-turned (dextral) and left-turned (sinistral) mouths

Answer 35

Negative Frequency Dependent Selection

Question 36

Number of offspring produced May survive fine, but not produce offspring Crossed wild and domestic sunflowers -fitness decreased in hybrid!!

Answer 36

Fecundity Selection

Question 37

reproduce once and then die

Answer 37

Semelparity

Question 38

reproduce more than once | It gets more complex

Answer 38

Iteroparity

Question 39

Usually ecologists just count daughters

Answer 39

Iteroparity

Question 40

Offspring produced at an earlier age increase fitness more

Answer 40

Life History - Population Increase

Question 41

A genotype that reproduces earlier and has a shorter generation time and higher fitness (as measured by r) than a genotype that reproduces later

Answer 41

Life History - Population Increase

Question 42

``` r = per capita rate of population increase R = er ```

Answer 42

Life History

Question 43

If one allele mutates into another

Answer 43

the allele will continuously appear in the population

Question 44

Shift from H-W equilibrium

Answer 44

Mutation

Question 45

80% are new mutations inherited from one parent

Answer 45

Achondroplasia

Question 46

mate with own genotype or phenotype

Answer 46

Assortative Mating

Question 47

mate with those of different genotype or phenotype

Answer 47

Disassortative Mating

Question 48

gene copies may be identical by descent

Answer 48

Inbreeding – Assortative

Question 49

Offspring between closely related individuals have lower fitness

Answer 49

Inbreeding Depression

Question 50

increased with inbreeding – people form Croatian islands

Answer 50

Hypertension

Question 51

20% of marriages between genetically related individuals

Answer 51

Inbreeding Depression

Question 52

Increase in heterozygotes over that predicted by H-W

Answer 52

Disassortative Mating

Question 53

Prefer mates with different Major Histocompatibility Complex

Answer 53

Disassortative Mating

Question 54

could drastically alter allele frequencies

Answer 54

Migration from a large population to a small one

Question 55

Will bring new alleles into a population

Answer 55

Migration