BIOLOGY & ANATOMY AS LEVEL
QUESTIONS AND VERIFIED SOLUTIONS
2025 UPDATED.
1. Which of the following is not a difference between gene expression in
prokaryotic and eukaryotic cells?
A. Prokaryotes lack introns
B. Eukaryotes perform transcription and translation simultaneously
C. Eukaryotic genes are monoisotopic
D. Prokaryotic mRNA lacks post-transcriptional modifications
Answer: B
Explanation: In prokaryotes, transcription and translation occur
simultaneously. In eukaryotes, transcription occurs in the nucleus, and
translation occurs in the cytoplasm — they do not happen at the same time.
2. DNA replication is:
A. Conservative
B. Semiconservative
C. Dispersive
D. Degenerative
Answer: B
Explanation: In semiconservative replication, each new DNA molecule
consists of one old strand and one newly synthesized strand.
3. The 3' end of a DNA strand contains which functional group?
A. Phosphate
B. Carboxyl
,C. Hydroxyl (-OH)
D. Methyl
Answer: C
Explanation: The 3' end has a free hydroxyl group, which is essential for the
addition of new nucleotides during DNA replication.
4. The 5' end of a nucleotide chain contains which functional group?
A. Phosphate (-PO₄)
B. Hydroxyl
C. Amine
D. Ketone
Answer: A
Explanation: The 5' end of a DNA strand contains a phosphate group
attached to the 5' carbon of the sugar molecule.
5. The end result of mitosis is:
A. 2 haploid nuclei
B. 4 diploid nuclei
C. 2 diploid nuclei
D. 4 haploid nuclei
Answer: C
Explanation: Mitosis produces two genetically identical diploid daughter cells
for growth or repair.
6. The result of meiosis I is:
A. 2 diploid nuclei
B. 4 haploid nuclei
C. 2 haploid nuclei
,D. 1 diploid nucleus
Answer: C
Explanation: Meiosis I reduces the chromosome number by half, forming two
haploid nuclei with duplicated chromosomes.
7. The result of meiosis II is:
A. 4 diploid nuclei
B. 4 haploid nuclei
C. 2 haploid nuclei
D. 2 diploid nuclei
Answer: B
Explanation: Meiosis II separates sister chromatids, resulting in four haploid
cells with unduplicated chromosomes.
8. How many NADPH and ATP molecules are produced in the light-
dependent reactions?
A. 1 NADPH & 1 ATP
B. 3 NADPH & 2 ATP
C. 2 NADPH & 3 ATP
D. 3 NADPH & 3 ATP
Answer: C
Explanation: The light-dependent reactions of photosynthesis typically
produce 2 NADPH and 3 ATP per water molecule split, used for the Calvin
cycle.
9. Which of the following is not a key difference between prokaryotic and
eukaryotic cells?
A. Prokaryotes lack a membrane-bound nucleus
, B. Eukaryotic cells are smaller in size
C. Only eukaryotes have membrane-bound organelles
D. Prokaryotes have circular DNA
Answer: B
Explanation: Eukaryotic cells are larger, not smaller. That makes this the
correct answer to a “which is not” question.
10. Permanent inactivation of an enzyme by a poison is what type of
inhibition?
A. Competitive
B. Allosteric
C. Reversible
D. Irreversible
Answer: D
Explanation: Irreversible inhibition occurs when a molecule (often a poison)
binds permanently to an enzyme, rendering it nonfunctional.
11. The part of an enzyme where the substrate binds is called the:
A. Regulatory site
B. Activation loop
C. Active site
D. Catalytic pocket
Answer: C
Explanation: The active site is the region where the enzyme binds its specific
substrate and catalyzes the reaction.
12. Oxaloacetate reacts with Acetyl-CoA in the citric acid cycle to form:
A. Malate
QUESTIONS AND VERIFIED SOLUTIONS
2025 UPDATED.
1. Which of the following is not a difference between gene expression in
prokaryotic and eukaryotic cells?
A. Prokaryotes lack introns
B. Eukaryotes perform transcription and translation simultaneously
C. Eukaryotic genes are monoisotopic
D. Prokaryotic mRNA lacks post-transcriptional modifications
Answer: B
Explanation: In prokaryotes, transcription and translation occur
simultaneously. In eukaryotes, transcription occurs in the nucleus, and
translation occurs in the cytoplasm — they do not happen at the same time.
2. DNA replication is:
A. Conservative
B. Semiconservative
C. Dispersive
D. Degenerative
Answer: B
Explanation: In semiconservative replication, each new DNA molecule
consists of one old strand and one newly synthesized strand.
3. The 3' end of a DNA strand contains which functional group?
A. Phosphate
B. Carboxyl
,C. Hydroxyl (-OH)
D. Methyl
Answer: C
Explanation: The 3' end has a free hydroxyl group, which is essential for the
addition of new nucleotides during DNA replication.
4. The 5' end of a nucleotide chain contains which functional group?
A. Phosphate (-PO₄)
B. Hydroxyl
C. Amine
D. Ketone
Answer: A
Explanation: The 5' end of a DNA strand contains a phosphate group
attached to the 5' carbon of the sugar molecule.
5. The end result of mitosis is:
A. 2 haploid nuclei
B. 4 diploid nuclei
C. 2 diploid nuclei
D. 4 haploid nuclei
Answer: C
Explanation: Mitosis produces two genetically identical diploid daughter cells
for growth or repair.
6. The result of meiosis I is:
A. 2 diploid nuclei
B. 4 haploid nuclei
C. 2 haploid nuclei
,D. 1 diploid nucleus
Answer: C
Explanation: Meiosis I reduces the chromosome number by half, forming two
haploid nuclei with duplicated chromosomes.
7. The result of meiosis II is:
A. 4 diploid nuclei
B. 4 haploid nuclei
C. 2 haploid nuclei
D. 2 diploid nuclei
Answer: B
Explanation: Meiosis II separates sister chromatids, resulting in four haploid
cells with unduplicated chromosomes.
8. How many NADPH and ATP molecules are produced in the light-
dependent reactions?
A. 1 NADPH & 1 ATP
B. 3 NADPH & 2 ATP
C. 2 NADPH & 3 ATP
D. 3 NADPH & 3 ATP
Answer: C
Explanation: The light-dependent reactions of photosynthesis typically
produce 2 NADPH and 3 ATP per water molecule split, used for the Calvin
cycle.
9. Which of the following is not a key difference between prokaryotic and
eukaryotic cells?
A. Prokaryotes lack a membrane-bound nucleus
, B. Eukaryotic cells are smaller in size
C. Only eukaryotes have membrane-bound organelles
D. Prokaryotes have circular DNA
Answer: B
Explanation: Eukaryotic cells are larger, not smaller. That makes this the
correct answer to a “which is not” question.
10. Permanent inactivation of an enzyme by a poison is what type of
inhibition?
A. Competitive
B. Allosteric
C. Reversible
D. Irreversible
Answer: D
Explanation: Irreversible inhibition occurs when a molecule (often a poison)
binds permanently to an enzyme, rendering it nonfunctional.
11. The part of an enzyme where the substrate binds is called the:
A. Regulatory site
B. Activation loop
C. Active site
D. Catalytic pocket
Answer: C
Explanation: The active site is the region where the enzyme binds its specific
substrate and catalyzes the reaction.
12. Oxaloacetate reacts with Acetyl-CoA in the citric acid cycle to form:
A. Malate
