Molecular Mechanisms

Question 1

name for a mutation that confers a novel property on the protein without necessarily altering its normal function

Answer 1

• novel property mutation

Question 2

name for a mutation associated with a reduction or a complete loss of one or more of the normal functions of a protein

Answer 2

• loss of function

Question 3

importance of loss of function mutation

Answer 3

• most common consequence of mutation

Question 4

name of inappropriate expression of a gene at an abnormal time and place

Answer 4

• heterochronic

- ectopic expression

Question 5

structural variants of hemoglobin

Answer 5

• alter the globin polypeptide without affecting the rate of synthesis

Question 6

thalassemias

Answer 6

• decreased synthesis of one or more of the globin chains

Question 7

hereditary persistence of fetal hemoglobin

Answer 7

• impaired perinatal switch from gamma to beta globin synthesis

Question 8

sickle cell disease illustrates a molecular mechanism of

Answer 8

• novel property mutation

Question 9

genetic passing of sickle cell disease

Answer 9

• autosomal recessive

Question 10

probability that the sibling of someone with sickle cell disease will be a carrier for that disease

Answer 10

• 2/3

Question 11

probably of a parent transmitting an autosomal recessive gene

Answer 11

• 1/2

Question 12

if the person has the trait, what is the probably that they are a carrier

Answer 12

1

Question 13

the study of the distribution of alleles in population and of how the frequencies of alleles and genotypes are maintained or changed

Answer 13

population genetics

Question 14

Hardy Weinberg Principle

Answer 14

p^2 + 2pq + q^2 = 1

p+q=1

Question 15

what is P

Answer 15

• reference allele

Question 16

what is Q

Answer 16

• alternate allele

Question 17

P^2

Answer 17

• frequency of homozygosity for reference

Question 18

2pq

Answer 18

• frequency of heterozygosity

Question 19

q^2

Answer 19

• frequency of homozygosity for alternate

Question 20

when we make an approximation, what is p

Answer 20

• around 1

- the condition is going to be so rare that not having it will almost be 1

Question 21

when we make an approximation, what is 2pq

Answer 21

• 2q

- because we assume p = 1

Question 22

if we make an approximation, what is 2pq/(p^2 + 2pq)

Answer 22

• 2pq

- just ignore the bottom

Question 23

population size in HWE

Answer 23

• population is large

Question 24

mating in HWE

Answer 24

• random mating

Question 25

allele frequency in HWE

Answer 25

• remains constant over time

Question 26

why do allele frequencies remain constant over time

Answer 26

• no selection for/against any genotype
• no immigration from a population with different allele frequencies
• no mutations

Question 27

effects of small populations

Answer 27

• genetic drift

- founder (bottleneck) effect

Question 28

fluctuations in the frequency of alleles resulting from chance occurrences operating in small populations

Answer 28

• genetic drift

Question 29

nonrandom distribution of alleles among the individuals who founded particular populations

Answer 29

• founder (bottleneck) effect

Question 30

population contains a number of subgroups that have remained genetically separate during modern times

example

Answer 30

• stratification

- African Americans and caucasians in the US

Question 31

choice of a mate because the mate possesses some particular trait

Answer 31

• assortative mating

Question 32

mating with someone who is related by descent

Answer 32

• consanguinity

Question 33

non random mating examples

Answer 33

• stratification
• assortative mating
• consanguinity

Question 34

exceptions to constant allele frequency

Answer 34

• mutation

- migration

Question 35

genetic passing of thalassemias

Answer 35

• autosomal recessive

Question 36

thalassemias illustrate which molecular mechanisms

Answer 36

• loss of function

- gene dosage

Question 37

alpha thalassemias confer resistance to

Answer 37

• malaria

Question 38

homology of alpha thalassemias

Answer 38

• between alpha 1 and alpha 2 genes

- but also intergenic regions

Question 39

most mutations in beta thalassemias

Answer 39

• missense
• nonsense
• frameshift mutations

Question 40

most common form of alpha thalassemias

Answer 40

• full deletions

Question 41

more than 200 pathogenic mutations in HBB described is an example of

Answer 41

• allelic heterogeneity

Question 42

heredity persistence of fetal hemoglobin results from

Answer 42

• point mutations in promoter gamma globin genes

Question 43

hereditary persistence of fetal hemoglobin illustrates which principle

Answer 43

• heterochronic or

- ectopic gene expression

Question 44

genetic inheritance of factor V Leiden

Answer 44

• autosomal dominant

Question 45

genetic inheritance of blood groups

Answer 45

• codominant

Question 46

factor V leiden illustrates molecular mechanism for

Answer 46

• gain of function

Question 47

name for mechanism where normal physiology requires more than 50% of fully active gene product to prevent disease

Answer 47

• haploinsufficiency

Question 48

haploinsufficiency refers to which phenotypes

Answer 48

• dominant

Question 49

name for mechanism where the abnormal protein causes an abnormal phenotype by interfering with the function of the product of the normal allele

Answer 49

• dominant negative effect