ch 6: mendelian genetics in populations (selection and mutation)

Question 1

how do we know if there was evolution within a population?

Answer 1

when allele frequencies change due to selection

Question 2

the genetic variation in a population will remain constant from one generation to the next in the absence of disturbing factors
- used to predict viral outcomes, creating vaccines ahead of time

Answer 2

hardy-weinberg equation principle

Question 3

what are the five means that hardy-weinberg can be disturbed/manipulated?

Answer 3

• selection
• mutation
• genetic drift
• gene flow
• nonrandom mating

Question 4

codominance

Answer 4

when two different dominant alleles both express equally (AB)
- creates a “medium”

Question 5

what is the hardy-weinberg equation

Answer 5

p squared plus 2pq plus q squared = 1

Question 6

what must p and q add up to

Answer 6

1

Question 7

two conclusions must be met for HW to be true, what are they?

Answer 7

1. the allele frequencies will not change in a population, generation after generation
2. observed allele frequencies in a population (i.e. p & q) can be used to calculate the observed genotype frequencies (p^2 + 2pq+q^2 = 1).

Question 8

how do we determine if a population is in HW or not?

Answer 8

1. calculate the genotype frequencies in a population
2. calculate the allele frequencies in the population
3. calculate what the allele frequencies would be in one generation of random mating

Question 9

never say that you’ve _________ a hypothesis

Answer 9

proved

Question 10

when an allele reaches 100% frequency at one loci; requires gene mutation to change it

Answer 10

fixation

Question 11

what happens when final allele frequencies and initial allele frequencies are the same, but the genotypes have changed?

Answer 11

doesn’t check condition 2 of HW - observed allele freq. can’t be used to calculate observed genotype freq. so not HW

Question 12

adaptive landscape

Answer 12

shows the range of fitness a population can experience

Question 13

the selection coefficient

Answer 13

s - depicts the strength of selection

Question 14

if the recessive allele is selected against, then AA = 1, Aa = 1, and aa - 1-s

Answer 14

s would be the disadvantage of the recessive genotype

Question 15

heterozygote superiority

Answer 15

when having both forms of an allele is more advantageous than both homozygous forms
- ex: sickle cell

Question 16

compound chromosomes

Answer 16

during crossing over, an entire “arm” of a chromosome is swapped
- getting a full centromere/full kinetochore is unlikely, which means the production of gametes is interfered with
- may result in containing both chromosomes, one, or neither
- only 1/4 zygotes are viable (4/16)

Question 17

can normal gametes join with compound chromosomes?

Answer 17

no

Question 18

underdominance

Answer 18

selection against the heterozygote

Question 19

frequency dependent selection

Answer 19

when the fitness of a pheno/genotype depends on the composition of the whole population
- elder-flowered orchid

Question 20

how do you quantify reproductive success in male vs. female plants?

Answer 20

pollinia: coherent mass of pollen grains that is transferred as a whole
fruit: forms upon pollination

Question 21

homozygous D: bad for intestines, don’t have CF (good ion channels)
heterozygous: helps w intestinal bacteria, don’t have CF
homozygous R: mutant, extremely low, has CF

Answer 21

cystic fibrosis