BIOD 121 MODULE 5 EXAM QUESTIONS AND CORRECT ANSWERS
WITH VERIFIED EXPLANATIONS 2026.
Which process results in the movement of water across a selectively permeable
membrane from an area of low solute concentration to high solute
concentration?
A. Diffusion
B. Active transport
C. Osmosis
D. Facilitated diffusion
Correct Answer: C
Explanation: Osmosis specifically refers to water movement across a
semipermeable membrane following its concentration gradient. Diffusion
involves solutes, while active transport requires energy.
2. In cellular respiration, which stage produces the largest amount of ATP?
A. Glycolysis
B. Krebs cycle
C. Electron transport chain
D. Fermentation
Correct Answer: C
Explanation: The electron transport chain generates the most ATP
through oxidative phosphorylation, while glycolysis and Krebs cycle
produce smaller amounts.
3. Which organelle is primarily responsible for protein synthesis?
A. Mitochondria
B. Ribosome
C. Golgi apparatus
D. Lysosome
Correct Answer: B
Explanation: Ribosomes are the sites of protein synthesis, translating
mRNA into polypeptide chains. Other organelles have different roles.
4. A mutation that does not change the amino acid sequence of a protein is
called:
, A. Missense mutation
B. Nonsense mutation
C. Silent mutation
D. Frameshift mutation
Correct Answer: C
Explanation: Silent mutations alter the DNA sequence without affecting
the amino acid due to redundancy in the genetic code.
5. Which phase of mitosis involves the alignment of chromosomes along the
equatorial plane?
A. Prophase
B. Metaphase
C. Anaphase
D. Telophase
Correct Answer: B
Explanation: During metaphase, chromosomes align at the metaphase
plate, ensuring proper separation.
6. Which molecule acts as the primary energy currency of the cell?
A. DNA
B. RNA
C. ATP
D. NADH
Correct Answer: C
Explanation: ATP stores and provides energy for cellular processes
through phosphate bond hydrolysis.
7. What is the main function of enzymes in biological systems?
A. Store genetic information
B. Catalyze biochemical reactions
C. Provide structural support
D. Transport molecules
Correct Answer: B
Explanation: Enzymes lower activation energy, speeding up chemical
reactions without being consumed.
,8. Which type of RNA carries amino acids to the ribosome?
A. mRNA
B. rRNA
C. tRNA
D. snRNA
Correct Answer: C
Explanation: Transfer RNA (tRNA) delivers specific amino acids during
protein synthesis.
9. In genetics, a phenotype refers to:
A. Genetic makeup
B. Observable traits
C. DNA sequence
D. Chromosome number
Correct Answer: B
Explanation: Phenotype is the physical expression of genes, influenced by
genotype and environment.
10.Which process produces gametes in humans?
A. Mitosis
B. Meiosis
C. Binary fission
D. Budding
Correct Answer: B
Explanation: Meiosis reduces chromosome number by half, producing
haploid gametes.
11.What is the function of the Golgi apparatus?
A. Protein synthesis
B. Lipid metabolism
C. Modification and packaging of proteins
D. Energy production
Correct Answer: C
Explanation: The Golgi modifies, sorts, and packages proteins for
secretion or use within the cell.
, 12.Which macromolecule is composed of amino acids?
A. Carbohydrates
B. Lipids
C. Proteins
D. Nucleic acids
Correct Answer: C
Explanation: Proteins are polymers of amino acids linked by peptide
bonds.
13.What is the role of chlorophyll in photosynthesis?
A. Absorb light energy
B. Produce glucose
C. Split water molecules
D. Fix carbon dioxide
Correct Answer: A
Explanation: Chlorophyll captures light energy, initiating the light-
dependent reactions.
14.Which part of the cell membrane provides fluidity?
A. Proteins
B. Cholesterol
C. Carbohydrates
D. Phospholipids
Correct Answer: B
Explanation: Cholesterol maintains membrane fluidity and stability
under varying temperatures.
15.Which phase of the cell cycle is the longest?
A. M phase
B. G1 phase
C. S phase
D. G2 phase
Correct Answer: B
Explanation: G1 is typically the longest phase, involving cell growth and
preparation for DNA replication.
WITH VERIFIED EXPLANATIONS 2026.
Which process results in the movement of water across a selectively permeable
membrane from an area of low solute concentration to high solute
concentration?
A. Diffusion
B. Active transport
C. Osmosis
D. Facilitated diffusion
Correct Answer: C
Explanation: Osmosis specifically refers to water movement across a
semipermeable membrane following its concentration gradient. Diffusion
involves solutes, while active transport requires energy.
2. In cellular respiration, which stage produces the largest amount of ATP?
A. Glycolysis
B. Krebs cycle
C. Electron transport chain
D. Fermentation
Correct Answer: C
Explanation: The electron transport chain generates the most ATP
through oxidative phosphorylation, while glycolysis and Krebs cycle
produce smaller amounts.
3. Which organelle is primarily responsible for protein synthesis?
A. Mitochondria
B. Ribosome
C. Golgi apparatus
D. Lysosome
Correct Answer: B
Explanation: Ribosomes are the sites of protein synthesis, translating
mRNA into polypeptide chains. Other organelles have different roles.
4. A mutation that does not change the amino acid sequence of a protein is
called:
, A. Missense mutation
B. Nonsense mutation
C. Silent mutation
D. Frameshift mutation
Correct Answer: C
Explanation: Silent mutations alter the DNA sequence without affecting
the amino acid due to redundancy in the genetic code.
5. Which phase of mitosis involves the alignment of chromosomes along the
equatorial plane?
A. Prophase
B. Metaphase
C. Anaphase
D. Telophase
Correct Answer: B
Explanation: During metaphase, chromosomes align at the metaphase
plate, ensuring proper separation.
6. Which molecule acts as the primary energy currency of the cell?
A. DNA
B. RNA
C. ATP
D. NADH
Correct Answer: C
Explanation: ATP stores and provides energy for cellular processes
through phosphate bond hydrolysis.
7. What is the main function of enzymes in biological systems?
A. Store genetic information
B. Catalyze biochemical reactions
C. Provide structural support
D. Transport molecules
Correct Answer: B
Explanation: Enzymes lower activation energy, speeding up chemical
reactions without being consumed.
,8. Which type of RNA carries amino acids to the ribosome?
A. mRNA
B. rRNA
C. tRNA
D. snRNA
Correct Answer: C
Explanation: Transfer RNA (tRNA) delivers specific amino acids during
protein synthesis.
9. In genetics, a phenotype refers to:
A. Genetic makeup
B. Observable traits
C. DNA sequence
D. Chromosome number
Correct Answer: B
Explanation: Phenotype is the physical expression of genes, influenced by
genotype and environment.
10.Which process produces gametes in humans?
A. Mitosis
B. Meiosis
C. Binary fission
D. Budding
Correct Answer: B
Explanation: Meiosis reduces chromosome number by half, producing
haploid gametes.
11.What is the function of the Golgi apparatus?
A. Protein synthesis
B. Lipid metabolism
C. Modification and packaging of proteins
D. Energy production
Correct Answer: C
Explanation: The Golgi modifies, sorts, and packages proteins for
secretion or use within the cell.
, 12.Which macromolecule is composed of amino acids?
A. Carbohydrates
B. Lipids
C. Proteins
D. Nucleic acids
Correct Answer: C
Explanation: Proteins are polymers of amino acids linked by peptide
bonds.
13.What is the role of chlorophyll in photosynthesis?
A. Absorb light energy
B. Produce glucose
C. Split water molecules
D. Fix carbon dioxide
Correct Answer: A
Explanation: Chlorophyll captures light energy, initiating the light-
dependent reactions.
14.Which part of the cell membrane provides fluidity?
A. Proteins
B. Cholesterol
C. Carbohydrates
D. Phospholipids
Correct Answer: B
Explanation: Cholesterol maintains membrane fluidity and stability
under varying temperatures.
15.Which phase of the cell cycle is the longest?
A. M phase
B. G1 phase
C. S phase
D. G2 phase
Correct Answer: B
Explanation: G1 is typically the longest phase, involving cell growth and
preparation for DNA replication.
