Molecular Mechanisms

Question 1

Novel property mutations definition

Answer 1

Mutation that confers a novel property on the protein without necessarily altering its normal functions

Question 2

Sickle cell disease affects the ____ of hemoglobin

Answer 2

Structure

Question 3

Sickle cell disease illustrates molecular mechanism of a ____ ____ mutation

Answer 3

novel property

Question 4

Why is sickle cell disease considered a novel property mutation?

Answer 4

Change in the amino acid sequence causes pathology by conferring a novel property on the protein without necessarily altering its normal function

Question 5

Population genetics is the study of the distribution of ______ in populations
and of how the frequencies of alleles and genotypes are maintained or changed

Answer 5

• alleles

Question 6

Genetic drift is defined as fluctuations in the _______ of alleles resulting from chance occurrences operating in small populations

Answer 6

-frequency

Question 7

Founder effects is defined as the [random/nonrandom] distribution of alleles among the individuals who founded particular subpopulations

Answer 7

-nonrandom

Question 8

In what kind of conditions will you use Hardy-Weinberg approximation?

Answer 8

Autosomal recessive, rare diseases

Question 9

In the approximation method, how do you determine q?

Answer 9

Take the square root of prevalence

Question 10

In the approximation method, p is about equal to __

Answer 10

1

Question 11

The _______ frequency is about twice the minor allele frequency, which is twice the square root of the prevalence

Answer 11

carrier; 2q

Question 12

In Hardy-Weinberg equilibrium, what are the assumptions that are made?

Answer 12

• Large population
• Random mating
• No selective pressures
• No immigration of different alleles
• No mutations

Question 13

Stratification

Answer 13

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

Ex: African Americans mating with other African Americans and not Caucasians

Question 14

Assortative mating

Answer 14

Choice of a mate because the mate possesses some particular trait

Ex: deaf person mating with another deaf person

Question 15

Consanguinity

Answer 15

Mating with someone who is related by descent

Question 16

What are some exceptions to a constant allele frequency?

Answer 16

• Selection for or against alleles
• Mutations
• Migration

Question 17

Which genotype of sickle cell disease confers resistance to malaria and results in a higher fitness than the other alleles?

Answer 17

Sickle cell trait (SC); reproduction is at a higher rate

Question 18

Thalassemias illustrate the molecular mechanisms of ___ _ ____ and gene dosage effects

Answer 18

• loss of function

Question 19

What is the genetic inheritance pattern of thalassemias?

Answer 19

Autosomal recessive

Question 20

Most common forms of alpha thalassemia are the result of ______

Answer 20

deletions

Question 21

Over 200 mutations are described to cause B thalassemias, this is an example of [allelic/locus] heterogeneity

Answer 21

• Allelic

Question 22

In B thalassemias, the mutations that occur are mostly missense, nonsense, and ______ mutations

Answer 22

-frameshift

Question 23

Hereditary persistence of fetal hemoglobin occurs due to _____ mutations in the promoter region of the γ globin genes

Answer 23

• point

Question 24

Hereditary persistence of fetal hemoglobin illustrates _______ or ectopic gene expression

Answer 24

• heterochronic (Inappropriate expression of a gene at an abnormal time or place)

Question 25

The most common inherited cause of deep vein thrombosis is

Answer 25

Factor V Leiden

Question 26

Activated protein __ usually would degrade factor V in the clotting cascade

Answer 26

C

Question 27

In factor V leiden, the expression of the phenotype is influenced by the ______

Answer 27

• Environment

Question 28

What is the pattern of inheritance for Factor V Leiden?

Answer 28

Autosomal dominant

Question 29

Haploinsufficiency refers to _____ phenotypes

Answer 29

• dominant

Question 30

Loss of half of the normal activity of a protein causes disease refers to

Answer 30

Haploinsufficiency

Question 31

Abnormal protein causes an abnormal phenotype by interfering with the function of the product of the normal allele refers to

Answer 31

Dominant negative effect

Question 32

One gene has multiple phenotypic effects, particularly when the effects are not obviously related refers to

Answer 32

Pleiotropy

Question 33

Severity of expression of the phenotype, although there is always some degree of expression present refers to

Answer 33

Variable expressivity

Question 34

Probability that a gene will have any phenotypic expression refers to

Answer 34

Penetrance