MCBG Genetics Hardy-Weinberg (H-W)

Question 1

Formula for Hardy-Weinberg equilibrium

Answer 1

P^2+2PQ+Q^2

Question 2

=f(homozygous dominant individuals (AA))

Answer 2

P^2

Question 3

=f(heterozygous individuals (Aa))

Answer 3

2PQ

Question 4

=f(homozygous recessive individuals (aa))

Answer 4

Q^2

Question 5

=f(dominant allele (A))

Answer 5

p

Question 6

=f(recessive allele (a))

Answer 6

q

Question 7

P+Q=?

Answer 7

1

Question 8

1-P=?

Answer 8

Q

Question 9

1-Q=?

Answer 9

P

Question 10

Which of these are Hardy-Weinberg assumptions?
A. Infinite population size
B. Random mating
C. No selection
D. No immigration
E. No emigration
F. No new mutations
G. No sex differences
H. All of the above
I. None of the above

Answer 10

H. All of the above

Question 11

Which of these disrupts Hardy-Weinberg equilibrium?
A. Consanguinity/inbreeding
B. Founder effect
C. Emigration/ Immigration
D. New mutations
E. Sex differences
F. All of the above
G. None of the above

Answer 11

F. All of the above
Consanguinity and inbreeding are forms of selection
Founder effect and isolation lead to tiny populations
Emigration and immigration disrupt H-W equilibrium

Question 12

What genetic disorder is prevalent in Finland?

Answer 12

XL Choroideremia hyperornitherinemia with gyrate atrophy of the choroid and retina

Question 13

What disease is prevalent in Blacks? What is the carrier frequency(2PQ) for this disease? What is the disease frequency for this disease (Q^2)?

Answer 13

Sickle Cell Anemia
2PQ=1/12
Q^2=1/600

Question 14

This disease presents with cherry red macula and no hepatosplenomegaly and is prevalent in Ashkhenazi jews. What is the disease? What is the carrier frequency? What is the disease frequency?

Answer 14

Tay Sachs
2PQ=1/30
Q^2=1/3600

Question 15

This disease is prevalent in Ashkenazi Jews and is classified as a leukodystrophy. A diagnostic test for it was subject of Greenberg v.Miami Children’s Hospital Research Institute. What is the disease? What is carrier frequency? What is disease frequency?

Answer 15

Canavan’s disease
2PQ=1/35 or 1/40
Q^2=1/6000

Question 16

This disease is prevalent in Greeks and Italians. It is a disease that effects ß subunit of Hb. It causes a mild microcytic anemia. What is the disease? What is the carrier frequency? What is the disease frequency?

Answer 16

ß Thalassemia
2PQ=1/30
Q^2=1/3600

Question 17

This disease is prevalent in Chinese and Southeast (SE) Asians. It is a disease that affects alpha subunit of Hb. It causes a mild microcytic anemia. What is the disease? What is the carrier frequency? What is the disease frequency?

Answer 17

Alpha thalassemia
2PQ=1/25
Q^2=1/2500

Question 18

It’s prevalent among Northern Europeans. Baby’s with this disease do not produce meconium. The gold standard diagnostic test for this disease is the sweat test. What is the disease? What is the carrier frequency? What is the disease frequency?

Answer 18

Cystic Fibrosis (CF)
2PQ=1/25
Q^2=1/2500

Question 19

Question 1

Patients with the autosomal recessive disease nemaline myopathy are found in Population “A” at a frequency of 1/490,000, but in Population “B” at 1/4,900. What is the mutant allele frequency in Population “A” ?

Answer

Answer 19

Correct Answer:
1/700
A: Q^2=1/490,000
Q=1/700

Question 20

Patients with the autosomal recessive disease nemaline myopathy are found in Population “A” at a frequency of 1/490,000, but in Population “B” at 1/4,900. What is the chance a woman from population A and a man from population B will have an affected child?

Answer 20

Correct Answer:	   
1/49,000
A: Q^2=1/490,000; Q=1/700; P=1
B:Q^2=1/4,900; Q=1/70; P=1
M: 2Q=1/350
D:2Q=1/35
Chance of affected child=(1/350)(1/35)(1/4)=1/49,000

Question 21

A woman comes from a population where the observed frequency of an autosomal recessive disease is 1/2,500. If the woman marries an unaffected man from a geographically distinct population where the frequency of this autosomal recessive disease is also 1/2,500, what is the chance that they will have an affected child?

Answer 21

Correct Answer:

1/2,500

Question 22

In the MN blood group system it is possible to know the genotype from the phenotype because

Answer 22

the alleles are codominant

Question 23

A population is in genetic equilibrium when ___.

Answer

Answer 23

Correct Answer:

allele and genotype frequencies do not change from generation to generation

Question 24

Examine the pedigree shown. The affected individuals, shown with solid symbols, have an autosomal recessive disease that occurs in the population at a frequency of 1/1,000,000,000,000. What is the chance that the father of the man indicated by the arrow is a carrier? Question part 2: This man indicated by the red arrow is obviously a carrier (he has an affected child)- can you predict which parent passed the mutant allele to him,?

Answer 24

1/500,000; yes, it most likely came from the mom

Question 25

What is the chance that a couple who are both healthy will have a child who is affected with cystic fibrosis, if the woman is from a Hispanic background where the carrier frequency is ~1/64, and her husband is caucasian, where the frequency of the disease is ~1/2500?
Answer

Answer 25

Correct Answer:
1/6400

M: 2PQ=1/64
D: Q^2=1/2500; Q=1/50; P=1; 2Q=1/25
Chance of affected child= (1/64)(1/25)(1/4)=1/6400

Question 26

• Question 3 –
0 out of 1 points

Person III-2 is considering having a child with III-1, but is worried about the AR disease his grandmother had. It is found in 1/100,000 in the population. What is III-2’s chance of being a carrier?

Answer 26

Correct Answer:
1/2
His chance of being a carrier is .5 b/c chance his father is a carrier is 1, so divide by 2=.5 for III2. It never gets less than carrier frequency of population.

Question 27

•Question 4

Person III-2 is considering having a child with III-1, but is worried about the AR disease his grandmother had. It is found in 1/10,000 in the population. What the couple’s chance of having an affected child?

Answer 27

Correct Answer:

1/400

Question 28

• Question 5

Examine the pedigree shown. Individuals I-1 and I-2 (and thus their immediate offspring) come from a population where the observed frequency of an autosomal recessive disease is 1/10,000. What is the chance that I-3 is a heterozygote for the disease?

Answer 28

Correct Answer:

1 (100%)

Question 29

• Question 6

Examine the pedigree. Individuals I-1 and I-2 (and thus their immediate offspring) come from a population where the observed frequency of an autosomal recessive disease is 1/10,000. What is the chance that individual II-4 is a carrier of the autosomal disease that affects those with the solid symbols?

Answer 29

Correct Answer:

1 (100%)

Question 30

• Question 7

Examine the pedigree. Individuals I-1 and I-2 (and thus their immediate offspring) come from a population where the observed frequency of an autosomal recessive disease is 1/10,000. Which of the women shown in the pedigree MUST be heterozygous at the locus related to the autosomal recessive disease that affects those with the solid symbols. Select all of the following who MUST be heterozygous.

Answer 30

Selected Answer:

I-3