Biology 340 Final Exam Questions And Answers
With Verified Solutions Graded A+ Latest Update
2025.
During interphase (any part of the cell cycle other than M-phase), DNA is packed into the nucleus by -
ANSWER by histones that pull the DNA into nucleosomes and chromatin fibers and by folding into
higher order structures
In a DNA double helix - ANSWER the purine guanine pairs with the pyrimidine cytosine
Which of the following is TRUE of a chromosome during G1 phase of the cell cycle?
it is a single molecule of DNA
it contains a telomere at the end of the leading strand
it contains a single origin of replication at the centromere
it contains a several centromeres - ANSWER it is a single molecule of DNA
Which of the following lists gives TRUE important characteristics of DNA structure?
2 polymers of ribose, running anti-parallel to one another, and hydrogen bonded together by nitrogenous
bases
2 complementary strands, joined together by covalent bonds between nitrogenous bases, and coiled into a
helix
2 polymers of nucleotides, each polymer covalently linked through phosphates and sugars of the
nucleotides, and the 2 polymers linked by hydrogen bonds between opposing nitrogenous bases
,2 complementary strands, running anti-parallel to one another, and held together by histones -
ANSWER 2 polymers of nucleotides, each polymer covalently linked through phosphates and sugars
of the nucleotides, and the 2 polymers linked by hydrogen bonds between opposing nitrogenous bases
Nucleosomes - ANSWER are formed into 30 nm chromatin fibers by the association of histone
protein H1
Modification of histone proteins influences chromatin structure and includes - ANSWER
methylation, acetylation, and phosphorylation of the N-terminal end of the histone
Epigenetic inheritance is - ANSWER inheritance of chromatin structure rather than DNA
sequence
DNA replication is a duplication of DNA that - ANSWER requires a primase
Okazaki fragments are short, newly synthesized DNA fragments that are - ANSWER formed on
the lagging strand template during DNA replication, and are complementary and anti-parallel to the
lagging strand template
Which of the following enzymes is NOT part of the elaborate DNA replication machine?
a. DNA primase
b. helicase
c. DNA polymerase
d. telomerase - ANSWER d. telomerase
DNA mutation repair mechanisms - ANSWER include nucleotide excision repair, which is the
removal and replacement of segments of DNA that contain errors such as pyrimidine dimers
CRISPR Cas9 - ANSWER is a molecular complex, composed of a synthetic guide RNA
molecule and Cas9 nuclease, and used for experimental gene editing
Origins of replication in human DNA are - ANSWER locations where the double-stranded DNA
is opened and replication proceeds in 2 directions with 2 replication forks
Which of the following statements about DNA replication is FALSE?
a. DNA replication is semi-conservative; DNA strands remain intact and serve as templates during
replication
b. DNA replication proceeds 5' to 3'; nucleotides are added only at the 3' end of a DNA strand
, c. helicase, DNA primase, and DNA polymerase are key enzymes in DNA replication
d. telomerase initiates DNA replication, which begins at the ends of the chromosomes - ANSWER
d. telomerase initiates DNA replication, which begins at the ends of the chromosomes
Which of the following is FALSE about the cell cycle?
a. it is controlled by constantly active cyclin-dependent kinases (Cdks)
b. it usually consists of 4 phases in eukaryotic cells
c. it has checkpoints that ensure the cell cycle does not progress unless all conditions are favorable
d. it includes a phase of DNA replication that precedes cell division - ANSWER a. it is
controlled by constantly active cyclin-dependent kinases (Cdks)
Which of the following occurs during M-phase but is NOT controlled by M-Cdk?
a. condensation of chromosomes
b. phosphorylation of lamins leading to breakdown of the nuclear envelope
c. formation of the mitotic spindle apparatus
d. activation of proteolytic enzymes that break cohesin and allow separation of sister chromatids -
ANSWER d. activation of proteolytic enzymes that break cohesin and allow separation of sister
chromatids
Chromosomes are aligned on the equator of the mitotic spindle and attached, via kinetochore
microtubules, to the centrosomes - ANSWER metaphase
Which of the following does NOT occur during anaphase?
a. centromeres split and chromatids separate
With Verified Solutions Graded A+ Latest Update
2025.
During interphase (any part of the cell cycle other than M-phase), DNA is packed into the nucleus by -
ANSWER by histones that pull the DNA into nucleosomes and chromatin fibers and by folding into
higher order structures
In a DNA double helix - ANSWER the purine guanine pairs with the pyrimidine cytosine
Which of the following is TRUE of a chromosome during G1 phase of the cell cycle?
it is a single molecule of DNA
it contains a telomere at the end of the leading strand
it contains a single origin of replication at the centromere
it contains a several centromeres - ANSWER it is a single molecule of DNA
Which of the following lists gives TRUE important characteristics of DNA structure?
2 polymers of ribose, running anti-parallel to one another, and hydrogen bonded together by nitrogenous
bases
2 complementary strands, joined together by covalent bonds between nitrogenous bases, and coiled into a
helix
2 polymers of nucleotides, each polymer covalently linked through phosphates and sugars of the
nucleotides, and the 2 polymers linked by hydrogen bonds between opposing nitrogenous bases
,2 complementary strands, running anti-parallel to one another, and held together by histones -
ANSWER 2 polymers of nucleotides, each polymer covalently linked through phosphates and sugars
of the nucleotides, and the 2 polymers linked by hydrogen bonds between opposing nitrogenous bases
Nucleosomes - ANSWER are formed into 30 nm chromatin fibers by the association of histone
protein H1
Modification of histone proteins influences chromatin structure and includes - ANSWER
methylation, acetylation, and phosphorylation of the N-terminal end of the histone
Epigenetic inheritance is - ANSWER inheritance of chromatin structure rather than DNA
sequence
DNA replication is a duplication of DNA that - ANSWER requires a primase
Okazaki fragments are short, newly synthesized DNA fragments that are - ANSWER formed on
the lagging strand template during DNA replication, and are complementary and anti-parallel to the
lagging strand template
Which of the following enzymes is NOT part of the elaborate DNA replication machine?
a. DNA primase
b. helicase
c. DNA polymerase
d. telomerase - ANSWER d. telomerase
DNA mutation repair mechanisms - ANSWER include nucleotide excision repair, which is the
removal and replacement of segments of DNA that contain errors such as pyrimidine dimers
CRISPR Cas9 - ANSWER is a molecular complex, composed of a synthetic guide RNA
molecule and Cas9 nuclease, and used for experimental gene editing
Origins of replication in human DNA are - ANSWER locations where the double-stranded DNA
is opened and replication proceeds in 2 directions with 2 replication forks
Which of the following statements about DNA replication is FALSE?
a. DNA replication is semi-conservative; DNA strands remain intact and serve as templates during
replication
b. DNA replication proceeds 5' to 3'; nucleotides are added only at the 3' end of a DNA strand
, c. helicase, DNA primase, and DNA polymerase are key enzymes in DNA replication
d. telomerase initiates DNA replication, which begins at the ends of the chromosomes - ANSWER
d. telomerase initiates DNA replication, which begins at the ends of the chromosomes
Which of the following is FALSE about the cell cycle?
a. it is controlled by constantly active cyclin-dependent kinases (Cdks)
b. it usually consists of 4 phases in eukaryotic cells
c. it has checkpoints that ensure the cell cycle does not progress unless all conditions are favorable
d. it includes a phase of DNA replication that precedes cell division - ANSWER a. it is
controlled by constantly active cyclin-dependent kinases (Cdks)
Which of the following occurs during M-phase but is NOT controlled by M-Cdk?
a. condensation of chromosomes
b. phosphorylation of lamins leading to breakdown of the nuclear envelope
c. formation of the mitotic spindle apparatus
d. activation of proteolytic enzymes that break cohesin and allow separation of sister chromatids -
ANSWER d. activation of proteolytic enzymes that break cohesin and allow separation of sister
chromatids
Chromosomes are aligned on the equator of the mitotic spindle and attached, via kinetochore
microtubules, to the centrosomes - ANSWER metaphase
Which of the following does NOT occur during anaphase?
a. centromeres split and chromatids separate
