GENETICS EXAM 2 QUESTIONS
AND CORRECT ANSWERS
What is the molecular mechanism for imprinting a
gene?
a. acetylation
b. methylation
c. phosphorylation
d. mutation
e. nitration
B
Genomic imprinting most commonly uses____ to
____genes.
Select one:
a. acetylation : activate
b. methylation : activate
c. phosphorylation : activate
d. methylation : deactivate
e. phosphorylation : deactivate
D
Individuals with three copies of most autosomes do
not survive. Individuals with an extra X chromosome,
however, survive with relatively mild (compared to
autosomal abnormalities) consequences. Why?
Select one:
a. Because the X chromosome determines sex only.
b. Because the X chromosome contains few genes
while autosomes contain a large number.
,c. Because the extra X chromosome(s) are inactivated.
d. None of the answers are correct.
e. All of the answers are correct.
C
The majority of calico cats are female. However, a few
rare males are observed. What is the genotype of a
male calico cat?
Select one:
a. XbYY
b. XBXb
c. XBXbY
d. XBY
e. XBXBY
C
Why is X-inactivation needed in humans?
Select one:
a. for dosage compensation
b. to eliminate X-linked lethal alleles
c. all the answers are correct
d. to inactivate genes coming from one parent
e. to protect against heterosis
A
Monoallelic expression is usually associated with
____________ in diploid organisms.
Select one:
a. dominant epistasis
b. dosage compensation
c. genomic imprinting
d. maternal effect
e. extranuclear inheritance
C
, Where is extra nuclear DNA located in mammalian
cells?
Select one:
a. Lysosomes
b. Chloroplasts
c. Endoplasmic reticulum
d. Mitochondria
e. Ribosomes
D
Prader-Willi Syndrome and Angelman Syndrome are
both associated with deletions of the same bands
from the long arm of chromosome 15. However, their
occurrence depends on whether the child inherited
the defective chromosome from the mother or the
father and the physical expression associated with
each disorder is very different. This is an example of
_____.
Select one:
a. sex-influenced inheritance
b. heteroplasmy
c. Mendelian inheritance
d. nuclear inheritance
e. genomic imprinting
E
Water snails demonstrate maternal effect in the
coiling of their shells. Gene product from the D
(dextral) allele induces right coiling whereas gene
product from the d (sinistral) allele induces left
coiling. Where is the gene for shell coiling likely
found?
Select one:
AND CORRECT ANSWERS
What is the molecular mechanism for imprinting a
gene?
a. acetylation
b. methylation
c. phosphorylation
d. mutation
e. nitration
B
Genomic imprinting most commonly uses____ to
____genes.
Select one:
a. acetylation : activate
b. methylation : activate
c. phosphorylation : activate
d. methylation : deactivate
e. phosphorylation : deactivate
D
Individuals with three copies of most autosomes do
not survive. Individuals with an extra X chromosome,
however, survive with relatively mild (compared to
autosomal abnormalities) consequences. Why?
Select one:
a. Because the X chromosome determines sex only.
b. Because the X chromosome contains few genes
while autosomes contain a large number.
,c. Because the extra X chromosome(s) are inactivated.
d. None of the answers are correct.
e. All of the answers are correct.
C
The majority of calico cats are female. However, a few
rare males are observed. What is the genotype of a
male calico cat?
Select one:
a. XbYY
b. XBXb
c. XBXbY
d. XBY
e. XBXBY
C
Why is X-inactivation needed in humans?
Select one:
a. for dosage compensation
b. to eliminate X-linked lethal alleles
c. all the answers are correct
d. to inactivate genes coming from one parent
e. to protect against heterosis
A
Monoallelic expression is usually associated with
____________ in diploid organisms.
Select one:
a. dominant epistasis
b. dosage compensation
c. genomic imprinting
d. maternal effect
e. extranuclear inheritance
C
, Where is extra nuclear DNA located in mammalian
cells?
Select one:
a. Lysosomes
b. Chloroplasts
c. Endoplasmic reticulum
d. Mitochondria
e. Ribosomes
D
Prader-Willi Syndrome and Angelman Syndrome are
both associated with deletions of the same bands
from the long arm of chromosome 15. However, their
occurrence depends on whether the child inherited
the defective chromosome from the mother or the
father and the physical expression associated with
each disorder is very different. This is an example of
_____.
Select one:
a. sex-influenced inheritance
b. heteroplasmy
c. Mendelian inheritance
d. nuclear inheritance
e. genomic imprinting
E
Water snails demonstrate maternal effect in the
coiling of their shells. Gene product from the D
(dextral) allele induces right coiling whereas gene
product from the d (sinistral) allele induces left
coiling. Where is the gene for shell coiling likely
found?
Select one:
