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WSU BIO 315 LECTURE Exam 2026-2027 BANK QUESTIONS
WITH DETAILED VERIFIED ANSWERS EXAM QUESTIONS
WILL COME FROM HERE (100% Latest Already Graded A+
Question 1
Which of the following best defines the term "genome"?
A) The complete set of proteins expressed by an organism
B) The complete set of genetic material present in a cell or organism
C) The sequence of RNA transcripts produced in a specific tissue
D) The collection of metabolic pathways encoded by an organism
Answer: B
Explanation: The genome is the entire complement of DNA, including all
genes and non-coding sequences, found in a cell or organism. Option A
describes the proteome, C describes the transcriptome, and D is
unrelated to the definition of genome.
Question 2
In eukaryotic cells, DNA is primarily associated with which proteins to
form chromatin?
A) Histones
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B) Ribosomal proteins
C) Polymerases
D) Transcription factors
Answer: A
Explanation: Histones are the core proteins that package DNA into
nucleosomes, the fundamental units of chromatin. Ribosomal proteins
are involved in ribosome assembly, polymerases in nucleic acid
synthesis, and transcription factors in gene regulation, not in the
primary packaging of DNA.
Question 3
Which enzyme is responsible for relieving torsional stress ahead of the
replication fork?
A) DNA helicase
B) DNA ligase
C) DNA gyrase
D) Primase
Answer: C
Explanation: DNA gyrase, a type of topoisomerase, introduces negative
supercoils to relieve the positive supercoiling that builds up ahead of the
replication fork. Helicase unwinds the helix, ligase seals nicks, and
primase synthesizes RNA primers.
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Question 4
The Meselson-Stahl experiment supported which model of DNA
replication?
A) Conservative
B) Semiconservative
C) Dispersive
D) Random
Answer: B
Explanation: The experiment used density-gradient centrifugation to
show that after one round of replication in N14 medium, DNA had an
intermediate density, and after two rounds, both intermediate and light
bands appeared, consistent with semiconservative replication where
each daughter molecule contains one old and one new strand.
Question 5
Which of the following is NOT a component of a nucleotide?
A) Nitrogenous base
B) Pentose sugar
C) Phosphate group
D) Amino acid
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Answer: D
Explanation: Nucleotides consist of a nitrogenous base, a pentose sugar,
and one or more phosphate groups. Amino acids are the building blocks
of proteins, not nucleotides.
Question 6
In RNA, which nitrogenous base replaces thymine found in DNA?
A) Adenine
B) Guanine
C) Cytosine
D) Uracil
Answer: D
Explanation: RNA uses uracil instead of thymine. Uracil pairs with
adenine during transcription and translation processes. Adenine,
guanine, and cytosine are present in both DNA and RNA.
Question 7
What is the directionality of DNA synthesis during replication?
A) 3' to 5'
B) 5' to 3'
C) Both directions simultaneously
D) Random
WSU BIO 315 LECTURE Exam 2026-2027 BANK QUESTIONS
WITH DETAILED VERIFIED ANSWERS EXAM QUESTIONS
WILL COME FROM HERE (100% Latest Already Graded A+
Question 1
Which of the following best defines the term "genome"?
A) The complete set of proteins expressed by an organism
B) The complete set of genetic material present in a cell or organism
C) The sequence of RNA transcripts produced in a specific tissue
D) The collection of metabolic pathways encoded by an organism
Answer: B
Explanation: The genome is the entire complement of DNA, including all
genes and non-coding sequences, found in a cell or organism. Option A
describes the proteome, C describes the transcriptome, and D is
unrelated to the definition of genome.
Question 2
In eukaryotic cells, DNA is primarily associated with which proteins to
form chromatin?
A) Histones
,2|Page
B) Ribosomal proteins
C) Polymerases
D) Transcription factors
Answer: A
Explanation: Histones are the core proteins that package DNA into
nucleosomes, the fundamental units of chromatin. Ribosomal proteins
are involved in ribosome assembly, polymerases in nucleic acid
synthesis, and transcription factors in gene regulation, not in the
primary packaging of DNA.
Question 3
Which enzyme is responsible for relieving torsional stress ahead of the
replication fork?
A) DNA helicase
B) DNA ligase
C) DNA gyrase
D) Primase
Answer: C
Explanation: DNA gyrase, a type of topoisomerase, introduces negative
supercoils to relieve the positive supercoiling that builds up ahead of the
replication fork. Helicase unwinds the helix, ligase seals nicks, and
primase synthesizes RNA primers.
,3|Page
Question 4
The Meselson-Stahl experiment supported which model of DNA
replication?
A) Conservative
B) Semiconservative
C) Dispersive
D) Random
Answer: B
Explanation: The experiment used density-gradient centrifugation to
show that after one round of replication in N14 medium, DNA had an
intermediate density, and after two rounds, both intermediate and light
bands appeared, consistent with semiconservative replication where
each daughter molecule contains one old and one new strand.
Question 5
Which of the following is NOT a component of a nucleotide?
A) Nitrogenous base
B) Pentose sugar
C) Phosphate group
D) Amino acid
, 4|Page
Answer: D
Explanation: Nucleotides consist of a nitrogenous base, a pentose sugar,
and one or more phosphate groups. Amino acids are the building blocks
of proteins, not nucleotides.
Question 6
In RNA, which nitrogenous base replaces thymine found in DNA?
A) Adenine
B) Guanine
C) Cytosine
D) Uracil
Answer: D
Explanation: RNA uses uracil instead of thymine. Uracil pairs with
adenine during transcription and translation processes. Adenine,
guanine, and cytosine are present in both DNA and RNA.
Question 7
What is the directionality of DNA synthesis during replication?
A) 3' to 5'
B) 5' to 3'
C) Both directions simultaneously
D) Random
