Practice Set 5

Question 1

Which of the following activities is not part of the chromatin remodeling mechanism?

Answer 1

Oxidation to H4.

Question 2

In Drosophila, heterochromatin

Answer 2

All are correct
a. is condensed throughout the cell cycle.
b. contains very small number genes.
c. is located near the centromeres.

Question 3

Epigenetics could cause gene silencing through

Answer 3

All are correct
a. DNA methylation
b. histone modification
c. non-coding RNA, e.g., miRNA, siRNA

Question 4

Position effect variation

Answer 4

All are correct
a. is an epigenetic phenomenon.
b. involves no DNA sequence change
c. was shown originally by using a chromosome inversion

Question 5

Which of the following describes the histones associated with the nucleosomes of active genes?

Answer 5

Rich in acetyl groups (i.e., hyperacetylated)

Question 6

Compared to heterochromatin, euchromatin is

Answer 6

rich in genes and comprised of loosely packed nucleosomes.

Question 7

The phenomenon in D. melanogaster known as Position-Effect Variegation (PEV) provides powerful evidence that:

Answer 7

chromatin structure is able to regulate gene expression.

Question 8

In mice, the igf2 allele is only expressed if

Answer 8

it is inherited from the father.

Question 9

Regions of a chromosome that are bundled in highly condensed chromatin are known as

Answer 9

heterochromatin.

Question 10

A Barr body refers to

Answer 10

None are correct

a. a sex-linked trait in cats.
b. a recessive trait in fruit flies.
c. an inactivated Y chromosome.
d. spore formation in Neurospora.

Question 11

Regarding genomic imprinting, which of the following statements is NOT true

Answer 11

It is an inheritance process of the classical Mendelian inheritance

Question 12

In mice the Igf-2 gene is maternally imprinted. To generate parthenogenic mice that inherited both Igf-2 alleles maternally, a genetic-engineering experiment was carried to

Answer 12

allow only one of the maternally derived alleles to express

Question 13

The phenotypical difference between the XX and XO genotypes can be best explained by

Answer 13

the XO genotype only has a single dose of genes located in two pseudoautosomal regions

Question 14

Regarding genomic imprinting, which of the following statements is NOT true

Answer 14

It is an inheritance process of the classical Mendelian inheritance

Question 15

Which of the following covalent modifications is NOT true?

Answer 15

H1 methylations are very important in opening chromatin.