MMSC491 Exam 1, Exam 2,
Exam 3,
Exam Study Guide – Practice
Questions with Verified
Answers. GRADED A+. Latest
2026/2027 Update
Table of Contents.
MMSC491 Exam 1....................................................... 2
MMSC491 Exam 2....................................................... 37
MMSC491 Exam 3........................................................ 91
,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?
Adenine and uracil
cytosine and uracil
guanine and uracil
uracil - Answer✔✔-guanine and uracil
Regarding the structure of bases in nucleic acids, which, if any, of the following
statements is incorrect?
Pyrimidines have a single heterocyclic ring consisting of four carbon atoms plus
two nitrogen atoms that are linked to the same carbonyl group
Purines have two heterocyclic rings, each with two nitrogen atoms
thymine = 5-methyluracil
pruines carry an amino group, unlike pyrimidines - Answer✔✔-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
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. - Answer✔✔-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. -
Answer✔✔-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.
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. - Answer✔✔-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
Exam 3,
Exam Study Guide – Practice
Questions with Verified
Answers. GRADED A+. Latest
2026/2027 Update
Table of Contents.
MMSC491 Exam 1....................................................... 2
MMSC491 Exam 2....................................................... 37
MMSC491 Exam 3........................................................ 91
,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?
Adenine and uracil
cytosine and uracil
guanine and uracil
uracil - Answer✔✔-guanine and uracil
Regarding the structure of bases in nucleic acids, which, if any, of the following
statements is incorrect?
Pyrimidines have a single heterocyclic ring consisting of four carbon atoms plus
two nitrogen atoms that are linked to the same carbonyl group
Purines have two heterocyclic rings, each with two nitrogen atoms
thymine = 5-methyluracil
pruines carry an amino group, unlike pyrimidines - Answer✔✔-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
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. - Answer✔✔-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. -
Answer✔✔-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.
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. - Answer✔✔-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
