1-selection

Question 1

under HWE do genotype /allele freq. change?

Answer 1

NO

Question 2

genetic drift leads to a loss of _____

Answer 2

genetic variation

Question 3

How do we regain lost genetic variation ?

Answer 3

mutation or migration

Question 4

genetic drift is strong when Ne is

Answer 4

small

Question 5

Ne = census pop size if:

Answer 5

all individuals are randomly mating and population is consistent

Question 6

what is the wahlund effect

Answer 6

decrease of heterozygosity in a population due to drift

Question 7

Fst measures what

Answer 7

genetic differentiation between groups

Question 8

Fst is high if:

Answer 8

groups have undergone a lot of genetic drift

Question 9

Fst is low if:

Answer 9

migration occurs between groups

Question 10

mutations have no/an effect on an organism’s phenotype and fitness

Answer 10

no

Question 11

most new mutations are

Answer 11

neutral

Question 12

most new non neutral mutations are

Answer 12

deleterious

Question 13

what acts to remove deleterious mutations from the population

Answer 13

selection

Question 14

beneficial mutations rise in freq due to __________ until they are ______

Answer 14

positive selection
fixed

Question 15

selection is strongest in :

Answer 15

large populations

Question 16

in large populations, nearly all segregating variants are ______ or ______

Answer 16

neutral or beneficial

Question 17

in small populations, _____ leads to fixation of a large number of neutral/deleterious variants

Answer 17

drift

Question 18

selection coefficient

Answer 18

strength of selection acting on a mutation

Question 19

if individuals with a variant have a 10% fitness reduction, s=

Answer 19

-0.1

Question 20

three specific types of selection

Answer 20

natural, sexual, artificial selection

Question 21

3 ways to describe selection

Answer 21

stabilizing, directional, diversifying

Question 22

drift acts on _______ loci in a genome

Answer 22

all

Question 23

selection acts on _______ loci

Answer 23

a specific

Question 24

Ne is reduced by

Answer 24

1. fluctuating population size
2. sex ratio distribution and non random mating increases

Question 25

selection is strongest when the variant is at ______ freq.

Answer 25

intermediate

Question 26

which mutations rise in freq. most rapidly?

Answer 26

dominant

Question 27

which mutations reach fixation the fastest

Answer 27

additive/co-dominant

Question 28

selection is inefficient when ______ mutations are at high freq. and ______ mutations are at low freq.

Answer 28

dominant
recessive

Question 29

what happens in a selective sweep

Answer 29

a positively selected variant that reaches high fixation/frequency drags along linked variants

Question 30

what is reduced during a selective sweep

Answer 30

diversity and heterozygosity

Question 31

if selection is so efficient at weeding out bad mutations and fixing good ones, why do we still have genetic disease?

Answer 31

hitchhiking
pleiotropy
drift

Question 32

epistasis

Answer 32

genetic interaction between different variants
AKA a gene can suppress the effect of another

Question 33

what is hitchhiking

Answer 33

deleterious mutations that would otherwise be lost due to selection can rise to high frequency by hitchhiking if they are linked to a positively selected variant

Question 34

what is pleiotropy

Answer 34

one variant/gene can have multiple phenotypic effects or even different effects in diff environments

Question 35

what leads to strong drift?

Answer 35

Small Ne

Question 36

in drift, the strong deleterious mutations may become in high/low frequency in small populations

Answer 36

high

Question 37

rare variants may be _____ to fitness since they tend to be recent mutations

Answer 37

moderately deleterious