Bank with Detailed Answers
1. Which organelle is responsible for producing ATP through cellular respiration?
A. Chloroplast
B. Ribosome
C. Mitochondrion
D. Endoplasmic Reticulum
Correct Answer: C. Mitochondrion
Rationale: Mitochondria are the "powerhouses" of the cell, converting glucose into ATP via
aerobic respiration.
2. What is the main function of tRNA during protein synthesis?
A. Replicates DNA
B. Delivers amino acids to the ribosome
C. Synthesizes mRNA
D. Transcribes DNA to RNA
Correct Answer: B. Delivers amino acids to the ribosome
Rationale: tRNA matches its anticodon with mRNA codons and brings the corresponding amino
acids during translation.
3. Which of the following best describes the structure of DNA?
A. Triple helix made of amino acids
B. Double helix composed of nucleotides
C. Single-stranded RNA chain
D. Double-layered protein helix
,Correct Answer: B. Double helix composed of nucleotides
Rationale: DNA consists of two strands of nucleotides twisted into a double helix.
4. What happens during the G2 phase of the cell cycle?
A. DNA replication
B. Cell division
C. Organelle replication and error checking
D. Chromosome alignment
Correct Answer: C. Organelle replication and error checking
Rationale: The G2 phase prepares the cell for mitosis by synthesizing proteins and checking for
DNA errors.
5. Which hormone regulates blood glucose levels by stimulating glucose uptake in cells?
A. Glucagon
B. Insulin
C. Cortisol
D. Thyroxine
Correct Answer: B. Insulin
Rationale: Insulin lowers blood glucose by allowing cells to absorb it, especially in the liver and
muscles.
6. In a food web, what would happen if all primary consumers were removed?
A. Increase in secondary consumers
B. Decrease in producers
C. Overgrowth of producers
D. No effect
Correct Answer: C. Overgrowth of producers
Rationale: Without herbivores, producers like plants and algae would grow uncontrollably.
7. What is the role of DNA polymerase in replication?
,A. Cuts the DNA strand
B. Unzips the double helix
C. Adds nucleotides to the growing strand
D. Transports DNA into the nucleus
Correct Answer: C. Adds nucleotides to the growing strand
Rationale: DNA polymerase reads the template strand and adds complementary nucleotides.
8. What genetic principle explains the independent inheritance of traits?
A. Law of Segregation
B. Law of Dominance
C. Law of Independent Assortment
D. Hardy-Weinberg Law
Correct Answer: C. Law of Independent Assortment
Rationale: This law states that genes for different traits segregate independently during
gamete formation.
9. Which component of the nervous system is responsible for involuntary actions like heart
rate and digestion?
A. Somatic Nervous System
B. Central Nervous System
C. Autonomic Nervous System
D. Sensory Nervous System
Correct Answer: C. Autonomic Nervous System
Rationale: The autonomic system regulates involuntary body functions such as heartbeat and
digestion.
10. What is the primary purpose of the Calvin Cycle in photosynthesis?
A. Release oxygen
B. Generate ATP
C. Fix carbon dioxide into glucose
D. Split water molecules
, Correct Answer: C. Fix carbon dioxide into glucose
Rationale: The Calvin Cycle uses ATP and NADPH to convert CO₂ into glucose in the chloroplast
stroma.
11. What is the function of restriction enzymes in biotechnology?
A. Create mRNA from DNA
B. Cut DNA at specific sequences
C. Replicate DNA
D. Synthesize proteins
Correct Answer: B. Cut DNA at specific sequences
Rationale: Restriction enzymes recognize specific nucleotide sequences and cut DNA at those
sites, useful in genetic engineering.
12. Which evolutionary process results from random changes in allele frequencies, especially in
small populations?
A. Natural selection
B. Gene flow
C. Genetic drift
D. Speciation
Correct Answer: C. Genetic drift
Rationale: Genetic drift involves random changes in allele frequencies and is more significant in
small populations.
13. What triggers the activation of helper T cells in the immune response?
A. Direct contact with pathogens
B. Binding to antigens presented by macrophages
C. Secretion of antibodies
D. Invasion of red blood cells
Correct Answer: B. Binding to antigens presented by macrophages
Rationale: Helper T cells are activated when they recognize antigens displayed on the surface
of antigen-presenting cells (like macrophages).
14. Which of the following structures regulates gene expression by binding to specific DNA
sequences in eukaryotic cells?