10/10/2024 11:44 AM
Biology 340 Final Exam Questions With
Correct Answers
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
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10/10/2024 11:44 AM
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
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10/10/2024 11:44 AM
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?