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Flashcards in final exam Deck (25):
1

hardy weinberg equilibrium

mathematical expression that predicts what proportions to expect in each of the three genotypic classes (looking only at 1 gene and assuming there are only 2 alleles)

2

genotypic frequencies determined by what

allelic frequencies (gene frequencies)

3

allelic frequencies

AA: p^2
Aa:2pq
aa: q^2
we can estimate gene and genotypic frequencies from homozygous recessive frequency (q^2=[aa])
also applies to autosomal genes and to X linked genes in females

4

assumptions of hardy weinberg equilibrium

frequencies above observed if we assume:
large, randomly mating population
no selection
no mutation
no migration (immigration or emigration)

5

changes in gene frequency

gene and genotypic frequencies will not remain at HW equilibrium if above not met

6

selection

all genotypes are not equally viable
fitness values (W) and selection coefficients (s) assigned to different groups
complete selection
partial selection
heterozygote advantage

7

complete selection

with complete selection against aa it is assigned an s value of 1
qnew=(qold/(1+qold))
qn=qo/(1+nqo)

8

partial selection

with partial selection against aa it is assigned s value less than 1 but greater than 0
qnew=(qold(1-sqold))/(1+sqold)

9

heterozygote advantage

both homozygotes are selected against (have s value greater than 0)
ex: sickle cell anemia in malaria environment
value of q will reach an equilibrium independent of the initial genotypic frequencies
q at equilibrium= s1/(s1+s3)

10

drift

if the mating population is small then dramatic fluctuations in gene and genotypic frequencies may be seen due to sampling error
founder's principle

11

founder's principle

"one time" drift event due to new population being founded from small sample of the original population

12

inbreeding

does not change gene frequency but changes genotypic frequencies (decrease in heterozygosity)

13

migration

affects frequencies due to change in population size

14

balanced polymorphisms

in nature, populations often exist with genotypic frequencies balanced at some level
may be due to neutral mutations, heterozygous advantage, equilibrium between mutation and selection, equilibrium between forward and backward mutation, or density-dependent selection

15

in animal males chiasmata are seen in

only in diploid structures
not spermatid, spermatocyte, or spermatogonium (sperm)

16

when 2 yellow mice are crossed what proportion are yellow fur

2/3

17

yellow gene= example of

recessive lethal

18

recessive mutation

loss of function mutations

19

coefficient of coincidence

proportion of double crossovers that occurred that were supposed to occur

20

human diploid cell has 46 chromosomes. how many dna molecules present in nucleus of one of these cells during G1

46

21

nondisjunction gives rise to

aneuploidy

22

tortoise shell cat always

has more than 1 X chromosome

23

most proteins required for mitochondrial function are coded for by

nuclear DNA

24

mitochondrial DNA includes

all genes for mitochondrial tRNAs
all genes for mitochondrial rRNAs
some genes for electron transport chain proteins

25

shotgun cloning is ___ and PCR is ___

shotgun cloning= in vivo
PCR= in vitro