BIOL180 Lesson 5 Quiz DNA, RNA,
and Protein Synthesis Questions And
Correct Answers (Verified Answers)
Plus Rationales 2026 Q&A | Instant
Download Pdf
1. Which molecule stores the hereditary information in most living
organisms?
A. ATP
B. Protein
C. Lipid
D. DNA
Answer: D. DNA
Rationale: DNA, or deoxyribonucleic acid, stores the genetic
information used to direct cellular activities and the production of
proteins. ATP primarily provides cellular energy, proteins perform
many structural and functional roles, and lipids are important
components of membranes and energy storage.
2. What is the basic building block of DNA?
A. Nucleotide
B. Amino acid
C. Monosaccharide
D. Fatty acid
Answer: A. Nucleotide
,Rationale: DNA is a nucleic acid polymer made from repeating
nucleotide subunits. Each DNA nucleotide contains a deoxyribose
sugar, a phosphate group, and one nitrogenous base. Amino acids
form proteins, while monosaccharides and fatty acids are components
of carbohydrates and lipids, respectively.
3. Which sugar is found in DNA?
A. Ribose
B. Glucose
C. Deoxyribose
D. Fructose
Answer: C. Deoxyribose
Rationale: DNA contains the five-carbon sugar deoxyribose. It differs
from ribose, the sugar found in RNA, because deoxyribose lacks an
oxygen atom at the 2′ carbon. This structural difference contributes to
the greater chemical stability of DNA.
4. Which nitrogenous base is found in DNA but normally not in
RNA?
A. Adenine
B. Thymine
C. Cytosine
D. Guanine
Answer: B. Thymine
Rationale: DNA contains adenine, thymine, cytosine, and guanine.
RNA generally contains uracil instead of thymine. Thus, thymine is
characteristic of DNA, whereas uracil is characteristic of RNA.
5. Which nitrogenous base pairs with adenine in DNA?
,A. Cytosine
B. Guanine
C. Uracil
D. Thymine
Answer: D. Thymine
Rationale: In double-stranded DNA, adenine pairs with thymine
through two hydrogen bonds. Cytosine pairs with guanine through
three hydrogen bonds. This complementary base pairing allows DNA
strands to serve as accurate templates during replication and
transcription.
6. Which base pairs with cytosine in DNA?
A. Guanine
B. Adenine
C. Thymine
D. Uracil
Answer: A. Guanine
Rationale: Cytosine and guanine form a complementary base pair in
DNA. They are connected by three hydrogen bonds, making the C–G
pair relatively strong. Adenine pairs with thymine, while uracil is
normally found in RNA.
7. What type of bond connects complementary nitrogenous bases
between the two DNA strands?
A. Peptide bond
B. Ionic bond
C. Hydrogen bond
D. Phosphodiester bond
Answer: C. Hydrogen bond
, Rationale: Hydrogen bonds connect complementary bases between
opposite DNA strands. Adenine and thymine form two hydrogen
bonds, while cytosine and guanine form three. Phosphodiester bonds
instead connect nucleotides within a single DNA or RNA strand.
8. What type of bond forms the sugar-phosphate backbone of DNA?
A. Hydrogen bond
B. Phosphodiester bond
C. Peptide bond
D. Glycosidic bond
Answer: B. Phosphodiester bond
Rationale: Phosphodiester bonds link the phosphate group of one
nucleotide to the sugar of another nucleotide, producing the DNA
backbone. Hydrogen bonds connect complementary bases between
strands, while peptide bonds connect amino acids in proteins.
9. The two strands of DNA are described as antiparallel because they:
A. contain different genetic information
B. have different nitrogenous bases
C. are separated by proteins
D. run in opposite directions
Answer: D. run in opposite directions
Rationale: DNA strands are antiparallel because one strand runs from
5′ to 3′ while the complementary strand runs from 3′ to 5′. This
orientation is essential for DNA replication because DNA polymerases
synthesize new DNA only in the 5′-to-3′ direction.
10. Which scientist's experimental work provided evidence that
DNA is the hereditary material in bacteriophages?
and Protein Synthesis Questions And
Correct Answers (Verified Answers)
Plus Rationales 2026 Q&A | Instant
Download Pdf
1. Which molecule stores the hereditary information in most living
organisms?
A. ATP
B. Protein
C. Lipid
D. DNA
Answer: D. DNA
Rationale: DNA, or deoxyribonucleic acid, stores the genetic
information used to direct cellular activities and the production of
proteins. ATP primarily provides cellular energy, proteins perform
many structural and functional roles, and lipids are important
components of membranes and energy storage.
2. What is the basic building block of DNA?
A. Nucleotide
B. Amino acid
C. Monosaccharide
D. Fatty acid
Answer: A. Nucleotide
,Rationale: DNA is a nucleic acid polymer made from repeating
nucleotide subunits. Each DNA nucleotide contains a deoxyribose
sugar, a phosphate group, and one nitrogenous base. Amino acids
form proteins, while monosaccharides and fatty acids are components
of carbohydrates and lipids, respectively.
3. Which sugar is found in DNA?
A. Ribose
B. Glucose
C. Deoxyribose
D. Fructose
Answer: C. Deoxyribose
Rationale: DNA contains the five-carbon sugar deoxyribose. It differs
from ribose, the sugar found in RNA, because deoxyribose lacks an
oxygen atom at the 2′ carbon. This structural difference contributes to
the greater chemical stability of DNA.
4. Which nitrogenous base is found in DNA but normally not in
RNA?
A. Adenine
B. Thymine
C. Cytosine
D. Guanine
Answer: B. Thymine
Rationale: DNA contains adenine, thymine, cytosine, and guanine.
RNA generally contains uracil instead of thymine. Thus, thymine is
characteristic of DNA, whereas uracil is characteristic of RNA.
5. Which nitrogenous base pairs with adenine in DNA?
,A. Cytosine
B. Guanine
C. Uracil
D. Thymine
Answer: D. Thymine
Rationale: In double-stranded DNA, adenine pairs with thymine
through two hydrogen bonds. Cytosine pairs with guanine through
three hydrogen bonds. This complementary base pairing allows DNA
strands to serve as accurate templates during replication and
transcription.
6. Which base pairs with cytosine in DNA?
A. Guanine
B. Adenine
C. Thymine
D. Uracil
Answer: A. Guanine
Rationale: Cytosine and guanine form a complementary base pair in
DNA. They are connected by three hydrogen bonds, making the C–G
pair relatively strong. Adenine pairs with thymine, while uracil is
normally found in RNA.
7. What type of bond connects complementary nitrogenous bases
between the two DNA strands?
A. Peptide bond
B. Ionic bond
C. Hydrogen bond
D. Phosphodiester bond
Answer: C. Hydrogen bond
, Rationale: Hydrogen bonds connect complementary bases between
opposite DNA strands. Adenine and thymine form two hydrogen
bonds, while cytosine and guanine form three. Phosphodiester bonds
instead connect nucleotides within a single DNA or RNA strand.
8. What type of bond forms the sugar-phosphate backbone of DNA?
A. Hydrogen bond
B. Phosphodiester bond
C. Peptide bond
D. Glycosidic bond
Answer: B. Phosphodiester bond
Rationale: Phosphodiester bonds link the phosphate group of one
nucleotide to the sugar of another nucleotide, producing the DNA
backbone. Hydrogen bonds connect complementary bases between
strands, while peptide bonds connect amino acids in proteins.
9. The two strands of DNA are described as antiparallel because they:
A. contain different genetic information
B. have different nitrogenous bases
C. are separated by proteins
D. run in opposite directions
Answer: D. run in opposite directions
Rationale: DNA strands are antiparallel because one strand runs from
5′ to 3′ while the complementary strand runs from 3′ to 5′. This
orientation is essential for DNA replication because DNA polymerases
synthesize new DNA only in the 5′-to-3′ direction.
10. Which scientist's experimental work provided evidence that
DNA is the hereditary material in bacteriophages?
