MMSC491 EXAM 1, 2, & 3 WITH WELL-
VERIFIED QUESTIONS AND ANSWERS||
ALREADY GRADED A+|| LATEST UPDATE 2026
Which, if any, of the following is not regularly an epigenetic phenomenon that
depends on DNA methylation or chromatin modification?
a. X-chromosome inactivation.
b. A position effect in which a gene is silenced by an inversion where both
breakpoints occur within a euchromatic environment.
c. Establishment of heterochromatin at a centromere.
d. Imprinting - ANSWER-b. A position effect in which a gene is silenced by an
inversion where both breakpoints occur within a euchromatic environment.
With respect to histone modifications, which, if any, of the following
statements, is true?
a. histone acetylation always means adding an acetyl group to the side chain of
a lysine residue.
b. in histone acetylation each lysine of the histone is acetylated.
c. in histone phosphorylation a phosphate group is transferred to the side chain
of a serine .
d. in histone methylation it is the DNA that coils around a nucleosome that is
methylated, not the histone itself. - ANSWER-a. histone acetylation always
means adding an acetyl group to the side chain of a lysine residue.
With respect to noncoding RNA (ncRNA) , which, if any, of the following
statements, is false?
a. Many long noncoding RNAs work in epigenetic regulation of gene
expression.
,b. Most regulatory long ncRNAs work as trans-acting regulators.
c. HOTAIR RNA is produced by a gene in the HOXC homeobox gene cluster at
12q13 but can regulate multiple genes within the HOXD gene cluster on
chromosome 2.
d. HOTAIR RNA works as a scaffold that binds specific protein regulators at its
two ends. - ANSWER-b. Most regulatory long ncRNAs work as trans-acting
regulators.
With respect to epimutations, which, if any, of the following statements, is
false, from a practical viewpoint?
a. The term epimutation means an unexpected change in chromatin
conformation, causing a g ene to be expressed in an abnormal way that is not
related to its base sequence.
b. A primary epimutation is a change in chromatin confirmation that is not
related directly to any change in the base sequence.
c. A secondary epimutation arises from a standard mutation that results in a
profound change of expression in a gene that regulates chromatin conformation.
d. A Òchromatin diseaseÓ is a disorder that is consistently caused by a primary
epimutation. - ANSWER-d. A Òchromatin diseaseÓ is a disorder that is
consistently caused by a primary epimutation.
Which, if any, of the following descriptions, is false?
a. Genomic imprinting in mammals really means that a very few genes are
expressed from one allele only, according to the sex of the parent.
b. Imprinted genes are often found in clusters of genes, many of which are
imprinted.
c. means that in a diploid cell two copies of the same chromosome are inherited
from one parent
d. Within an imprinted gene cluster, all genes on one of the two parental
chromosomes are silenced, but the equivalent genes on the other parental
chromosome are not subject to silencing. - ANSWER-d. Within an imprinted
gene cluster, all genes on one of the two parental chromosomes are silenced, but
,the equivalent genes on the other parental chromosome are not subject to
silencing.
With reference to imprinting disorders, which, if any, of the following
statements is false?
a. About one quarter of individuals with Angelman syndrome lack a paternal
chromosome 15.
b. With the exception of abnormal chromosome segregation, imprinting
disorders always result from a deletion or inactivating mutation within, or
spanning the imprinted gene cluster.
c. In some imprinting disorders, disease results from inappropriate biallelic
expression of a gene.
d. Angelman and Prader-Willi syndrome are very different disorders but can be
caused by precisely the same large deletion at 15q11-q13. - ANSWER-b. With
the exception of abnormal chromosome segregation, imprinting disorders
always result from a deletion or inactivating mutation within, or spanning the
imprinted gene cluster.
With regard to the molecular pathogenesis of facioscapulohumeral dystrophy,
which, if any, of the following can be implicated in the pathogenesis?
a. a variable number of tandem DNA repeats.
b. increased heterochromatin.
c. activation of a retrogene.
d. a regulator of methylation. - ANSWER-b. increased heterochromatin.
Which, if any, of the following descriptions, is inaccurate?The epigenome.......
a. means the totality of epigenetic settings in a cell.
b. is variable between tissues.
c. does not vary between cells of the same type
d. can change in response to changes in the environment. - ANSWER-c. does
not vary between cells of the same type
, Assisted reproductive technology studies modeled in mice have demonstrated....
a. intracytoplasmic sperm injection induces primary epimutations
b. altered the patterns of DNA methylation
c. altered imprinting patterns that are transmitted to subsequent generations.
d. modified splice site junctions - ANSWER-a. intracytoplasmic sperm injection
induces primary epimutations
A mutation that does not cause a disease but that is unstable at mitosis and
meiosis and can change into a pathogenic mutation.
a. a post-zygotic (somatic) mutation
b. a missense mutation
c. a dynamic mutation
d. a premutation - ANSWER-d. a premutation
A pathogenic mutation that is unstable at mitosis and meiosis and can result in
progressively severe phenotypes.
a. a post-zygotic (somatic) mutation
b. a missense mutation
c. a dynamic mutation
d. a premutation - ANSWER-c. a dynamic mutation
A type of mutation that results in genetic mosaicism.
a. a post-zygotic (somatic) mutation
b. a missense mutation
c. a dynamic mutation
d. a premutation - ANSWER-a. a post-zygotic (somatic) mutation
VERIFIED QUESTIONS AND ANSWERS||
ALREADY GRADED A+|| LATEST UPDATE 2026
Which, if any, of the following is not regularly an epigenetic phenomenon that
depends on DNA methylation or chromatin modification?
a. X-chromosome inactivation.
b. A position effect in which a gene is silenced by an inversion where both
breakpoints occur within a euchromatic environment.
c. Establishment of heterochromatin at a centromere.
d. Imprinting - ANSWER-b. A position effect in which a gene is silenced by an
inversion where both breakpoints occur within a euchromatic environment.
With respect to histone modifications, which, if any, of the following
statements, is true?
a. histone acetylation always means adding an acetyl group to the side chain of
a lysine residue.
b. in histone acetylation each lysine of the histone is acetylated.
c. in histone phosphorylation a phosphate group is transferred to the side chain
of a serine .
d. in histone methylation it is the DNA that coils around a nucleosome that is
methylated, not the histone itself. - ANSWER-a. histone acetylation always
means adding an acetyl group to the side chain of a lysine residue.
With respect to noncoding RNA (ncRNA) , which, if any, of the following
statements, is false?
a. Many long noncoding RNAs work in epigenetic regulation of gene
expression.
,b. Most regulatory long ncRNAs work as trans-acting regulators.
c. HOTAIR RNA is produced by a gene in the HOXC homeobox gene cluster at
12q13 but can regulate multiple genes within the HOXD gene cluster on
chromosome 2.
d. HOTAIR RNA works as a scaffold that binds specific protein regulators at its
two ends. - ANSWER-b. Most regulatory long ncRNAs work as trans-acting
regulators.
With respect to epimutations, which, if any, of the following statements, is
false, from a practical viewpoint?
a. The term epimutation means an unexpected change in chromatin
conformation, causing a g ene to be expressed in an abnormal way that is not
related to its base sequence.
b. A primary epimutation is a change in chromatin confirmation that is not
related directly to any change in the base sequence.
c. A secondary epimutation arises from a standard mutation that results in a
profound change of expression in a gene that regulates chromatin conformation.
d. A Òchromatin diseaseÓ is a disorder that is consistently caused by a primary
epimutation. - ANSWER-d. A Òchromatin diseaseÓ is a disorder that is
consistently caused by a primary epimutation.
Which, if any, of the following descriptions, is false?
a. Genomic imprinting in mammals really means that a very few genes are
expressed from one allele only, according to the sex of the parent.
b. Imprinted genes are often found in clusters of genes, many of which are
imprinted.
c. means that in a diploid cell two copies of the same chromosome are inherited
from one parent
d. Within an imprinted gene cluster, all genes on one of the two parental
chromosomes are silenced, but the equivalent genes on the other parental
chromosome are not subject to silencing. - ANSWER-d. Within an imprinted
gene cluster, all genes on one of the two parental chromosomes are silenced, but
,the equivalent genes on the other parental chromosome are not subject to
silencing.
With reference to imprinting disorders, which, if any, of the following
statements is false?
a. About one quarter of individuals with Angelman syndrome lack a paternal
chromosome 15.
b. With the exception of abnormal chromosome segregation, imprinting
disorders always result from a deletion or inactivating mutation within, or
spanning the imprinted gene cluster.
c. In some imprinting disorders, disease results from inappropriate biallelic
expression of a gene.
d. Angelman and Prader-Willi syndrome are very different disorders but can be
caused by precisely the same large deletion at 15q11-q13. - ANSWER-b. With
the exception of abnormal chromosome segregation, imprinting disorders
always result from a deletion or inactivating mutation within, or spanning the
imprinted gene cluster.
With regard to the molecular pathogenesis of facioscapulohumeral dystrophy,
which, if any, of the following can be implicated in the pathogenesis?
a. a variable number of tandem DNA repeats.
b. increased heterochromatin.
c. activation of a retrogene.
d. a regulator of methylation. - ANSWER-b. increased heterochromatin.
Which, if any, of the following descriptions, is inaccurate?The epigenome.......
a. means the totality of epigenetic settings in a cell.
b. is variable between tissues.
c. does not vary between cells of the same type
d. can change in response to changes in the environment. - ANSWER-c. does
not vary between cells of the same type
, Assisted reproductive technology studies modeled in mice have demonstrated....
a. intracytoplasmic sperm injection induces primary epimutations
b. altered the patterns of DNA methylation
c. altered imprinting patterns that are transmitted to subsequent generations.
d. modified splice site junctions - ANSWER-a. intracytoplasmic sperm injection
induces primary epimutations
A mutation that does not cause a disease but that is unstable at mitosis and
meiosis and can change into a pathogenic mutation.
a. a post-zygotic (somatic) mutation
b. a missense mutation
c. a dynamic mutation
d. a premutation - ANSWER-d. a premutation
A pathogenic mutation that is unstable at mitosis and meiosis and can result in
progressively severe phenotypes.
a. a post-zygotic (somatic) mutation
b. a missense mutation
c. a dynamic mutation
d. a premutation - ANSWER-c. a dynamic mutation
A type of mutation that results in genetic mosaicism.
a. a post-zygotic (somatic) mutation
b. a missense mutation
c. a dynamic mutation
d. a premutation - ANSWER-a. a post-zygotic (somatic) mutation
