CBSE Class 11 Biology Practice MCQs for Term & Annual Exams

(NCERT-Based | Exam-Focused | With Answers & Concept-Clearing Explanations)

Section A: Diversity in Living World (10 MCQs)

Q1. The branch of biology that deals with identification and classification of organisms is called:
A. Ecology
B. Genetics
C. Taxonomy
D. Physiology

Answer: C. Taxonomy
Explanation: Taxonomy involves identification, nomenclature, and classification of organisms based on similarities and differences.

Q2. In binomial nomenclature, the scientific name is written in:
A. Capital letters
B. Italics
C. Bold letters
D. Underlined block letters

Answer: B. Italics
Explanation: Scientific names are written in italics (or underlined separately when handwritten).

Q3. Which kingdom includes organisms with cell wall made of chitin?
A. Plantae
B. Monera
C. Protista
D. Fungi

Answer: D. Fungi
Explanation: Fungal cell walls are composed mainly of chitin.

Q4. Mycoplasma differs from other bacteria because it:
A. Has a nucleus
B. Lacks ribosomes
C. Lacks cell wall
D. Is multicellular

Answer: C. Lacks cell wall
Explanation: Mycoplasma is the smallest living cell and lacks a rigid cell wall.

Q5. Which plant group shows alternation of generations clearly?
A. Algae
B. Bryophytes
C. Gymnosperms
D. Angiosperms

Answer: B. Bryophytes
Explanation: Bryophytes show distinct gametophytic and sporophytic phases.

Q6. Amphibians of plant kingdom are:
A. Algae
B. Bryophytes
C. Pteridophytes
D. Gymnosperms

Answer: B. Bryophytes
Explanation: Bryophytes require water for fertilization.

Q7. Which of the following has naked seeds?
A. Angiosperms
B. Bryophytes
C. Gymnosperms
D. Pteridophytes

Answer: C. Gymnosperms
Explanation: Seeds are not enclosed in fruits in gymnosperms.

Q8. Viruses are considered non-living outside host cells because they:
A. Lack proteins
B. Lack cellular structure
C. Cannot reproduce
D. Lack nucleic acids

Answer: C. Cannot reproduce
Explanation: Viruses replicate only inside living host cells.

Q9. Which taxonomic category is the most inclusive?
A. Species
B. Genus
C. Family
D. Kingdom

Answer: D. Kingdom
Explanation: Kingdom includes all organisms with basic similarities.

Q10. Lichens represent a symbiotic relationship between:
A. Algae and bacteria
B. Algae and fungi
C. Fungi and moss
D. Algae and protozoa

Answer: B. Algae and fungi
Explanation: Algae provide food; fungi provide protection.

Section B: Structural Organisation in Animals & Plants (10 MCQs)

Q11. Which tissue provides flexibility to plant parts?
A. Parenchyma
B. Collenchyma
C. Sclerenchyma
D. Xylem

Answer: B. Collenchyma
Explanation: Collenchyma provides mechanical support with flexibility.

Q12. Xylem tissue helps in:
A. Food transport
B. Gas exchange
C. Water transport
D. Photosynthesis

Answer: C. Water transport
Explanation: Xylem conducts water and minerals from roots to leaves.

Q13. Which connective tissue connects muscle to bone?
A. Ligament
B. Tendon
C. Cartilage
D. Areolar tissue

Answer: B. Tendon
Explanation: Tendons are strong and non-elastic.

Q14. Blood is classified as:
A. Muscular tissue
B. Nervous tissue
C. Epithelial tissue
D. Connective tissue

Answer: D. Connective tissue
Explanation: Blood connects organs by transporting substances.

Q15. The functional unit of kidney is:
A. Neuron
B. Nephron
C. Alveolus
D. Sarcomere

Answer: B. Nephron
Explanation: Nephrons filter blood and form urine.

Q16. Which muscle works involuntarily and is non-striated?
A. Skeletal muscle
B. Cardiac muscle
C. Smooth muscle
D. Striated muscle

Answer: C. Smooth muscle
Explanation: Smooth muscles are found in visceral organs.

Q17. Which tissue stores fat in the body?
A. Areolar tissue
B. Adipose tissue
C. Cartilage
D. Bone

Answer: B. Adipose tissue
Explanation: Adipose tissue stores fat and insulates body.

Q18. The outermost layer of dicot stem is:
A. Cortex
B. Endodermis
C. Epidermis
D. Pericycle

Answer: C. Epidermis
Explanation: Epidermis protects plant body.

Q19. Phloem is responsible for transport of:
A. Water
B. Minerals
C. Food
D. Gases

Answer: C. Food
Explanation: Phloem transports sugars produced in photosynthesis.

Q20. The structural unit of muscle contraction is:
A. Myofibril
B. Sarcomere
C. Actin
D. Myosin

Answer: B. Sarcomere
Explanation: Shortening of sarcomeres causes contraction.

Section C: Cell Structure & Function (10 MCQs)

Q21. The fluid mosaic model was proposed by:
A. Watson and Crick
B. Singer and Nicolson
C. Schleiden and Schwann
D. Robert Hooke

Answer: B. Singer and Nicolson
Explanation: The model describes plasma membrane as dynamic and fluid.

Q22. Which organelle synthesizes proteins?
A. Golgi body
B. Ribosome
C. Lysosome
D. SER

Answer: B. Ribosome
Explanation: Ribosomes translate mRNA into proteins.

Q23. Which organelle is called the powerhouse of cell?
A. Chloroplast
B. Lysosome
C. Mitochondria
D. Nucleus

Answer: C. Mitochondria
Explanation: ATP is produced during respiration.

Q24. Which organelle is absent in prokaryotes?
A. Ribosome
B. Plasma membrane
C. Nucleus
D. Cytoplasm

Answer: C. Nucleus
Explanation: Prokaryotes lack membrane-bound nucleus.

Q25. Cristae are associated with:
A. Chloroplast
B. Golgi apparatus
C. Mitochondria
D. ER

Answer: C. Mitochondria
Explanation: Cristae increase surface area for ATP synthesis.

Q26. Lysosomes contain:
A. Digestive enzymes
B. DNA
C. Lipids
D. Pigments

Answer: A. Digestive enzymes
Explanation: They digest worn-out organelles.

Q27. Which plastid stores starch?
A. Chloroplast
B. Chromoplast
C. Amyloplast
D. Elaioplast

Answer: C. Amyloplast
Explanation: Amyloplasts store starch.

Q28. The largest cell in human body is:
A. Neuron
B. Muscle cell
C. Ovum
D. RBC

Answer: C. Ovum
Explanation: Human ovum is the largest cell.

Q29. The membrane surrounding vacuole is called:
A. Plasmalemma
B. Tonoplast
C. Cell wall
D. Cristae

Answer: B. Tonoplast
Explanation: Tonoplast regulates transport in vacuole.

Q30. Prokaryotic ribosomes are:
A. 80S
B. 70S
C. 60S
D. 90S

Answer: B. 70S
Explanation: Smaller ribosomes compared to eukaryotes.

Section D: Plant Physiology (10 MCQs)

Q31. Water moves from soil to root hairs mainly by:
A. Diffusion
B. Osmosis
C. Active transport
D. Mass flow

Answer: B. Osmosis
Explanation: Due to difference in water potential.

Q32. Upward movement of water in plants occurs through:
A. Phloem
B. Cortex
C. Xylem
D. Cambium

Answer: C. Xylem
Explanation: Xylem conducts water and minerals.

Q33. Transpiration mainly occurs through:
A. Cuticle
B. Lenticels
C. Stomata
D. Root hairs

Answer: C. Stomata
Explanation: Maximum water loss occurs via stomata.

Q34. The primary photosynthetic pigment is:
A. Chlorophyll b
B. Carotene
C. Chlorophyll a
D. Xanthophyll

Answer: C. Chlorophyll a
Explanation: It directly participates in photosynthesis.

Q35. Light reaction of photosynthesis takes place in:
A. Stroma
B. Thylakoids
C. Cytoplasm
D. Matrix

Answer: B. Thylakoids
Explanation: Light energy is trapped here.

Q36. End product of glycolysis is:
A. Lactic acid
B. Pyruvic acid
C. Acetyl CoA
D. Ethanol

Answer: B. Pyruvic acid
Explanation: Glucose breaks down into pyruvate.

Q37. Which hormone promotes cell elongation?
A. Cytokinin
B. Ethylene
C. Auxin
D. ABA

Answer: C. Auxin
Explanation: Auxins promote stem elongation.

Q38. Respiration without oxygen is:
A. Aerobic respiration
B. Anaerobic respiration
C. Photorespiration
D. Transpiration

Answer: B. Anaerobic respiration
Explanation: Produces less ATP.

Q39. Magnesium is a component of:
A. Hemoglobin
B. Chlorophyll
C. Cytochrome
D. Enzymes

Answer: B. Chlorophyll
Explanation: Magnesium is central atom of chlorophyll.

Q40. Loss of water vapour from plant parts is called:
A. Respiration
B. Transpiration
C. Guttation
D. Translocation

Answer: B. Transpiration
Explanation: Occurs mainly through stomata.

Section E: Human Physiology (10 MCQs)

Q41. The functional unit of lung is:
A. Bronchus
B. Bronchiole
C. Alveolus
D. Trachea

Answer: C. Alveolus
Explanation: Site of gas exchange.

Q42. Which enzyme is present in saliva?
A. Pepsin
B. Trypsin
C. Amylase
D. Lipase

Answer: C. Amylase
Explanation: Digests starch.

Q43. Universal donor blood group is:
A. A
B. B
C. AB
D. O

Answer: D. O
Explanation: Lacks A and B antigens.

Q44. Pacemaker of heart is:
A. AV node
B. SA node
C. Purkinje fibres
D. Bundle of His

Answer: B. SA node
Explanation: Initiates heartbeat.

Q45. Which hormone lowers blood sugar level?
A. Glucagon
B. Adrenaline
C. Insulin
D. Thyroxine

Answer: C. Insulin
Explanation: Secreted by pancreas.

Q46. Main nitrogenous waste in humans is:
A. Ammonia
B. Uric acid
C. Urea
D. Creatinine

Answer: C. Urea
Explanation: Humans are ureotelic.

Q47. Vitamin required for blood clotting is:
A. Vitamin A
B. Vitamin B
C. Vitamin C
D. Vitamin K

Answer: D. Vitamin K
Explanation: Needed for synthesis of clotting factors.

Q48. Fight-or-flight hormone is:
A. Insulin
B. Cortisol
C. Adrenaline
D. Thyroxine

Answer: C. Adrenaline
Explanation: Prepares body for emergencies.

Q49. Which part of brain maintains balance?
A. Cerebrum
B. Cerebellum
C. Medulla
D. Hypothalamus

Answer: B. Cerebellum
Explanation: Coordinates posture and balance.

Q50. Functional unit of muscle contraction is:
A. Myosin
B. Actin
C. Sarcomere
D. Myofibril

Answer: C. Sarcomere
Explanation: Shortening of sarcomere causes contraction.

✅ These NCERT-aligned practice MCQs are ideal for CBSE Class 11 term tests, annual exams, and concept revision.