22/12/2025
🧬 Biology MCQs 2025
1. Which biomolecule acts as an enzyme in living cells?
A) Lipid
B) Carbohydrate
C) Protein
D) Nucleic acid
2. The fluid mosaic model explains the structure of:
A) Cell wall
B) Nucleus
C) Plasma membrane
D) Cytoplasm
3. Which organelle is involved in intracellular digestion?
A) Ribosome
B) Golgi apparatus
C) Lysosome
D) Mitochondria
4. In photosynthesis, oxygen is released during:
A) Calvin cycle
B) Dark reaction
C) Photolysis of water
D) CO₂ fixation
5. DNA replication occurs during which phase of cell cycle?
A) G₁ phase
B) G₂ phase
C) S phase
D) M phase
6. Which blood group is known as universal donor?
A) AB⁺
B) A⁻
C) O⁻
D) O⁺
7. The functional unit of kidney is:
A) Ureter
B) Nephron
C) Glomerulus
D) Loop of Henle
8. Which hormone lowers blood glucose level?
A) Glucagon
B) Adrenaline
C) Thyroxine
D) Insulin
9. Which structure connects muscle to bone?
A) Ligament
B) Tendon
C) Cartilage
D) Joint
10. Genetic information is transferred from DNA to ribosome by:
A) rRNA
B) mRNA
C) tRNA
D) snRNA
🧫 Genetics & Biotechnology
11. Crossing over occurs during:
A) Prophase-I
B) Metaphase-I
C) Pachytene stage
D) Anaphase-I
12. Restriction enzymes are used to:
A) Join DNA fragments
B) Cut DNA at specific sites
C) Copy DNA
D) Translate DNA
13. The study of heredity is called:
A) Taxonomy
B) Ecology
C) Genetics
D) Evolution
14. Phenotype refers to:
A) Genetic makeup
B) Physical expression of genes
C) Chromosome number
D) DNA sequence
15. Which base pairing is correct in DNA?
A) A–C
B) G–T
C) A–T
D) C–A
🌱 Plant Biology
16. Transpiration mainly occurs through:
A) Cuticle
B) Lenticels
C) Stomata
D) Roots
17. Which tissue transports food in plants?
A) Xylem
B) Cambium
C) Cortex
D) Phloem
18. The opening and closing of stomata is controlled by:
A) Epidermal cells
B) Guard cells
C) Companion cells
D) Root hairs
🧠 Human Physiology
19. The pacemaker of heart is:
A) AV node
B) Bundle of His
C) Purkinje fibers
D) SA node
20. Which vitamin is synthesized in skin?
A) Vitamin A
B) Vitamin C
C) Vitamin D
D) Vitamin K
