MMSC491 Exam I, Exam II, Exam III,
Complete Exam Study Guide – Practice
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TABLE OF CONTENTS
❖ MMSc491 Exam 1……………………..…...2
❖ MMSc491 Exam 2………………..…………31
❖ MMSc491 Exam 3…………………..………49
1|Page
,MMSC491 Exam 1
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 - ANS ✔✔-guanine and uracil
Regarding the structure of bases in nucleic acids, which, if any, of the following statements is incorrect?
a) Pyrimidines have a single heterocyclic ring consisting of four carbon atoms plus two nitrogen atoms that
are linked to the same carbonyl group
b) Purines have two heterocyclic rings, each with two nitrogen atoms
c) thymine = 5-methyluracil
d) pruines carry an amino group, unlike pyrimidines - ANS ✔✔-purines carry an amino group, unlike
pyrimidines
Regarding the sugar residues in nucleic acids, which, if any, of the following statements is incorrect?
The sugar is always based on a heterocyclic ring that consists of one oxygen atom and four carbon atoms, one of
which is connected to a fifth carbon atom, the 5 carbon 5' carbon atom
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,The internal sugar residues in a DNA strand normally have free hydroxyl groups, unlike those in an RNA strand.
Bases are covalently linked to the carbon 1' atoms of the sugars.
Neighboring sugar residues are linked to each other by a phosphodiester bond that connects the 3' carbon atom
on one sugar to the 5' carbon atom of its neighbor. - ANS ✔✔-The internal sugar residues in a DNA strand
normally have free hydroxyl groups, unlike those in an RNA strand.
Regarding the 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.
d) The synthesis of new DNA strands always proceeds in the 5' → 3' direction. - ANS ✔✔-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.
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.
3|Page
, 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. -
ANS ✔✔-c) A DNA polymerase always requires a DNA template to synthesize a complementary DNA.
Which is the best definition of noncoding RNA?
a) A mutant mRNA that is not capable of making a protein.
b) Any RNA sequence that is not translated to make a protein
c) Any RNA sequence in an mRNA, or in the primary transcript used to make the mRNA, that is not translated to
make a protein.
d) A functional RNA that is not translated to make a protein. - ANS ✔✔-d) A functional RNA that is not
translated to make a protein.
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.
4|Page
Complete Exam Study Guide – Practice
Questions with Verified Answers |100%
Guaranteed Value Pack GRADED A+.
Latest 2026/2027 Update
TABLE OF CONTENTS
❖ MMSc491 Exam 1……………………..…...2
❖ MMSc491 Exam 2………………..…………31
❖ MMSc491 Exam 3…………………..………49
1|Page
,MMSC491 Exam 1
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 - ANS ✔✔-guanine and uracil
Regarding the structure of bases in nucleic acids, which, if any, of the following statements is incorrect?
a) Pyrimidines have a single heterocyclic ring consisting of four carbon atoms plus two nitrogen atoms that
are linked to the same carbonyl group
b) Purines have two heterocyclic rings, each with two nitrogen atoms
c) thymine = 5-methyluracil
d) pruines carry an amino group, unlike pyrimidines - ANS ✔✔-purines carry an amino group, unlike
pyrimidines
Regarding the sugar residues in nucleic acids, which, if any, of the following statements is incorrect?
The sugar is always based on a heterocyclic ring that consists of one oxygen atom and four carbon atoms, one of
which is connected to a fifth carbon atom, the 5 carbon 5' carbon atom
2|Page
,The internal sugar residues in a DNA strand normally have free hydroxyl groups, unlike those in an RNA strand.
Bases are covalently linked to the carbon 1' atoms of the sugars.
Neighboring sugar residues are linked to each other by a phosphodiester bond that connects the 3' carbon atom
on one sugar to the 5' carbon atom of its neighbor. - ANS ✔✔-The internal sugar residues in a DNA strand
normally have free hydroxyl groups, unlike those in an RNA strand.
Regarding the 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.
d) The synthesis of new DNA strands always proceeds in the 5' → 3' direction. - ANS ✔✔-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.
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.
3|Page
, 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. -
ANS ✔✔-c) A DNA polymerase always requires a DNA template to synthesize a complementary DNA.
Which is the best definition of noncoding RNA?
a) A mutant mRNA that is not capable of making a protein.
b) Any RNA sequence that is not translated to make a protein
c) Any RNA sequence in an mRNA, or in the primary transcript used to make the mRNA, that is not translated to
make a protein.
d) A functional RNA that is not translated to make a protein. - ANS ✔✔-d) A functional RNA that is not
translated to make a protein.
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.
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