MMSC 491 Exam 1 NEWEST EXAM 2026-2027
COMPLETE 550 QUESTIONS AND CORRECT
DETAILED ANSWERS (VERIFIED ANSWERS)
ALREADY GRADED A+
A DNA variant in the ALX gene is observed at a frequency of 0.012 %, how would this variant
be described?
A. polymorphism
B. rare variant
C. mutation
D. transgene - CORRECT ANSWER: A
During gene expression, the initial RNA transcript needs to undergo processing to make a mature
RNA, either a ____ ____ RNA or a ____ ___ RNA - CORRECT ANSWER: coding, noncoding
For many of our genes, the initial RNA transcript needs to be cleaved into pieces. Some of the
pieces, called ____ ____, are discarded, but other alternating pieces called ___ ____ are retained
and fused in the same linear order as their order when transcribed. - CORRECT ANSWER:
introns, exons
If we take the number of chromosomes in a haploid sperm cell or egg cell to be n and the total
content of genomic DNA to be C, what is the number of chromosomes and the total genomic
DNA content of a diploid G1 phase cell and in a diploid G2 phase cell from the same organism.
a) n chromosomes, DNA content of 2C in G1; 2n chromosomes, DNA content of 4C in G2.
b) 2n chromosomes, DNA content of 2C in G1; 4n chromosomes, DNA content of 4C in G2.
c) 2n chromosomes, DNA content of 2C in G1; 4n chromosomes, DNA content of 2C in G2.
,d) 2n chromosomes, DNA content of 2C in G1; 2n chromosomes, DNA content of 4C in G2. -
CORRECT ANSWER: D
In a DNA double helix each type of base forms a stable base pair with only one type of base.
When bases on an RNA strand are involved in base pairing, which bases can form stable base
pairs with more than one type of base?
a) Adenine and uracil
b) Cytosine and uracil
c) Guanine and uracil
d) Uracil - CORRECT ANSWER: C
In addition to coding sequence, which is generally very highly conserved, what additional
percentage of our genome is highly to moderately conserved?
a) 0.4%
b) 4%
c) 14%
d) 24% - CORRECT ANSWER: B
Microsatellite DNA is expected to show variation with respect to
A. DNA sequence
,B. Chromosome location
C. Copy number
D. Replication efficiency - CORRECT ANSWER: C
Nucleic acid hybridization assays are normally carried out under relaxed hybridization
stringency (to maximize the chances of heteroduplex formation) but afterwards, washes are
carried out that can be designed to favor perfectly matched sequences only by changing some
parameter. Which, if any, of the following changes would be consistent with that aim?
a) An increase in temperature.
b) An increase in salt concentration.
c) An increase in the concentration of a polar molecule, such as urea or formamide.
d) Both A and C
E) A, B, and C - CORRECT ANSWER: D
One of the DNA strands serves as a ________ for an RNA polymerase to synthesize a
complementary RNA - CORRECT ANSWER: template
Patients with disorders of the mistmatched repair system can be easily diagnosed using which
type of laboratory analysis?
A. Next generation DNA sequencing
B. PCR
C. Cytogenic methods (chromosome analysis)
D. Biochemical assays - CORRECT ANSWER: C
, Patients with Xeroderma Pigmentosum have defects in which DNA repair system?
A. Mismatch repair
B. Nucleotide excision repair
C. Single strand break repair
D. Homologous recombination - CORRECT ANSWER: B
Regarding DNA replication and DNA synthesis, which, if any, of the following statements is
incorrect?
a) The leading strand is replicated continuously.
b) The lagging strand is replicated discontinuously: the new DNA is synthesized as short
pieces of DNA that must be ligated together.
c) A DNA polymerase always requires a DNA template to synthesize a complementary DNA.
d) A DNA polymerase requires a short RNA primer when synthesizing new DNA strands using a
DNA template. - CORRECT ANSWER: C
Regarding DNA replication, which, if any, of the following statements is incorrect?
a) DNA replication is said to be semi-conservative because for each DNA helix only one
strand serves as a template for new DNA synthesis.
b) The two DNA strands of the parental DNA helix are unwound using a DNA helicase.
c) The replication fork marks the point at which DNA is actively being replicated from a
single DNA duplex to form new DNA strands.
COMPLETE 550 QUESTIONS AND CORRECT
DETAILED ANSWERS (VERIFIED ANSWERS)
ALREADY GRADED A+
A DNA variant in the ALX gene is observed at a frequency of 0.012 %, how would this variant
be described?
A. polymorphism
B. rare variant
C. mutation
D. transgene - CORRECT ANSWER: A
During gene expression, the initial RNA transcript needs to undergo processing to make a mature
RNA, either a ____ ____ RNA or a ____ ___ RNA - CORRECT ANSWER: coding, noncoding
For many of our genes, the initial RNA transcript needs to be cleaved into pieces. Some of the
pieces, called ____ ____, are discarded, but other alternating pieces called ___ ____ are retained
and fused in the same linear order as their order when transcribed. - CORRECT ANSWER:
introns, exons
If we take the number of chromosomes in a haploid sperm cell or egg cell to be n and the total
content of genomic DNA to be C, what is the number of chromosomes and the total genomic
DNA content of a diploid G1 phase cell and in a diploid G2 phase cell from the same organism.
a) n chromosomes, DNA content of 2C in G1; 2n chromosomes, DNA content of 4C in G2.
b) 2n chromosomes, DNA content of 2C in G1; 4n chromosomes, DNA content of 4C in G2.
c) 2n chromosomes, DNA content of 2C in G1; 4n chromosomes, DNA content of 2C in G2.
,d) 2n chromosomes, DNA content of 2C in G1; 2n chromosomes, DNA content of 4C in G2. -
CORRECT ANSWER: D
In a DNA double helix each type of base forms a stable base pair with only one type of base.
When bases on an RNA strand are involved in base pairing, which bases can form stable base
pairs with more than one type of base?
a) Adenine and uracil
b) Cytosine and uracil
c) Guanine and uracil
d) Uracil - CORRECT ANSWER: C
In addition to coding sequence, which is generally very highly conserved, what additional
percentage of our genome is highly to moderately conserved?
a) 0.4%
b) 4%
c) 14%
d) 24% - CORRECT ANSWER: B
Microsatellite DNA is expected to show variation with respect to
A. DNA sequence
,B. Chromosome location
C. Copy number
D. Replication efficiency - CORRECT ANSWER: C
Nucleic acid hybridization assays are normally carried out under relaxed hybridization
stringency (to maximize the chances of heteroduplex formation) but afterwards, washes are
carried out that can be designed to favor perfectly matched sequences only by changing some
parameter. Which, if any, of the following changes would be consistent with that aim?
a) An increase in temperature.
b) An increase in salt concentration.
c) An increase in the concentration of a polar molecule, such as urea or formamide.
d) Both A and C
E) A, B, and C - CORRECT ANSWER: D
One of the DNA strands serves as a ________ for an RNA polymerase to synthesize a
complementary RNA - CORRECT ANSWER: template
Patients with disorders of the mistmatched repair system can be easily diagnosed using which
type of laboratory analysis?
A. Next generation DNA sequencing
B. PCR
C. Cytogenic methods (chromosome analysis)
D. Biochemical assays - CORRECT ANSWER: C
, Patients with Xeroderma Pigmentosum have defects in which DNA repair system?
A. Mismatch repair
B. Nucleotide excision repair
C. Single strand break repair
D. Homologous recombination - CORRECT ANSWER: B
Regarding DNA replication and DNA synthesis, which, if any, of the following statements is
incorrect?
a) The leading strand is replicated continuously.
b) The lagging strand is replicated discontinuously: the new DNA is synthesized as short
pieces of DNA that must be ligated together.
c) A DNA polymerase always requires a DNA template to synthesize a complementary DNA.
d) A DNA polymerase requires a short RNA primer when synthesizing new DNA strands using a
DNA template. - CORRECT ANSWER: C
Regarding DNA replication, which, if any, of the following statements is incorrect?
a) DNA replication is said to be semi-conservative because for each DNA helix only one
strand serves as a template for new DNA synthesis.
b) The two DNA strands of the parental DNA helix are unwound using a DNA helicase.
c) The replication fork marks the point at which DNA is actively being replicated from a
single DNA duplex to form new DNA strands.
