CBSE Class 11 Biology – Transport in Plants | MCQs with Answers & Explanations (NCERT Based)

Course & Examination Details

Course: CBSE Class 11 Biology
Unit: Unit IV – Plant Physiology
Chapter: Chapter 11 – Transport in Plants
Prescribed Textbook: NCERT
Board: CBSE

CBSE Board Examination Relevance

• MCQs test conceptual clarity and application
• Frequently asked in school exams and internal assessments
• Based strictly on NCERT definitions, processes, and theories

Section A: Diffusion (MCQs 1–12)

Q1. Diffusion is best defined as movement of molecules:
A. Against concentration gradient using energy
B. From lower to higher concentration
C. From higher to lower concentration without energy
D. Through xylem vessels only

Correct Answer: C
Explanation: Diffusion is a passive process driven by concentration gradient, requiring no metabolic energy.

Q2. Which factor does NOT affect diffusion rate?
A. Temperature
B. Molecular size
C. Concentration gradient
D. Presence of ATP

Correct Answer: D
Explanation: Diffusion does not require ATP; it depends on physical factors like temperature and gradient.

Q3. Diffusion is most effective over:
A. Long distances
B. Short distances
C. Vascular tissues
D. Entire plant body

Correct Answer: B
Explanation: Diffusion is slow and effective only across short distances such as cell membranes.

Q4. Exchange of gases in leaves occurs mainly by:
A. Active transport
B. Osmosis
C. Diffusion
D. Mass flow

Correct Answer: C
Explanation: Oxygen and carbon dioxide move along concentration gradients through diffusion.

Q5. Which substance diffuses out during photosynthesis?
A. Carbon dioxide
B. Oxygen
C. Water
D. Minerals

Correct Answer: B
Explanation: Oxygen produced during photosynthesis diffuses out of leaves.

Q6. Diffusion occurs fastest in:
A. Solids
B. Liquids
C. Gases
D. Cell walls

Correct Answer: C
Explanation: Molecules move most freely in gases, making diffusion fastest.

Q7. Diffusion is non-directional because:
A. It uses energy
B. Molecules move randomly
C. It requires membranes
D. It involves ions

Correct Answer: B
Explanation: Random molecular motion causes diffusion in all directions.

Q8. Which plant structure facilitates diffusion of gases?
A. Xylem
B. Phloem
C. Stomata
D. Cortex

Correct Answer: C
Explanation: Stomata provide openings for gaseous diffusion.

Q9. Why is diffusion insufficient in tall plants?
A. Requires energy
B. Too fast
C. Too slow for long distances
D. Occurs only in roots

Correct Answer: C
Explanation: Diffusion alone cannot meet long-distance transport needs.

Q10. Increase in temperature causes diffusion rate to:
A. Decrease
B. Stop
C. Increase
D. Remain constant

Correct Answer: C
Explanation: Higher temperature increases kinetic energy of molecules.

Q11. Which is NOT transported by diffusion in plants?
A. CO₂
B. O₂
C. Minerals to leaves
D. Water vapour

Correct Answer: C
Explanation: Long-distance mineral transport occurs through xylem, not diffusion.

Q12. Diffusion does not require membranes because:
A. It is energy driven
B. It is pressure driven
C. It occurs due to concentration gradient
D. It is directional

Correct Answer: C
Explanation: Diffusion depends only on concentration difference.

Section B: Osmosis (MCQs 13–25)

Q13. Osmosis involves movement of:
A. Solutes only
B. Water only
C. Ions only
D. Gases only

Correct Answer: B
Explanation: Osmosis is movement of water across a semi-permeable membrane.

Q14. Osmosis occurs through:
A. Permeable membrane
B. Impermeable membrane
C. Semi-permeable membrane
D. Cell wall

Correct Answer: C
Explanation: Semi-permeable membrane allows only water to pass.

Q15. A cell placed in hypotonic solution becomes:
A. Plasmolysed
B. Flaccid
C. Turgid
D. Dead

Correct Answer: C
Explanation: Water enters the cell, increasing turgidity.

Q16. Plasmolysis occurs when a cell is placed in:
A. Hypotonic solution
B. Isotonic solution
C. Hypertonic solution
D. Distilled water

Correct Answer: C
Explanation: Water moves out due to lower external water potential.

Q17. Water potential is highest in:
A. Concentrated solution
B. Pure water
C. Cell sap
D. Hypertonic solution

Correct Answer: B
Explanation: Pure water has maximum free energy.

Q18. Which pressure prevents plant cells from bursting?
A. Osmotic pressure
B. Root pressure
C. Wall pressure
D. Atmospheric pressure

Correct Answer: C
Explanation: Rigid cell wall provides wall pressure.

Q19. Osmosis is important for:
A. Gas exchange
B. Mineral transport
C. Water absorption by roots
D. Translocation of food

Correct Answer: C
Explanation: Root hairs absorb water by osmosis.

Q20. Movement of water out of cell is called:
A. Endosmosis
B. Exosmosis
C. Diffusion
D. Active transport

Correct Answer: B
Explanation: Exosmosis refers to outward movement of water.

Q21. Osmosis is a special case of diffusion because:
A. It uses energy
B. It involves all molecules
C. It involves only water
D. It is directional

Correct Answer: C
Explanation: Osmosis is diffusion of water specifically.

Q22. Which component lowers water potential?
A. Pressure potential
B. Solute potential
C. Gravity potential
D. Matrix potential

Correct Answer: B
Explanation: Dissolved solutes reduce free energy of water.

Q23. Guard cell movement depends mainly on:
A. Diffusion
B. Osmosis
C. Active transport only
D. Root pressure

Correct Answer: B
Explanation: Osmotic changes control turgidity of guard cells.

Q24. Isotonic solution causes cell to:
A. Burst
B. Shrink
C. Show no net water movement
D. Die

Correct Answer: C
Explanation: Equal water potential prevents net movement.

Q25. Osmosis occurs only when:
A. Temperature is high
B. Pressure exists
C. Membrane is present
D. ATP is available

Correct Answer: C
Explanation: Semi-permeable membrane is essential.

Section C: Transpiration (MCQs 26–38)

Q26. Transpiration is loss of:
A. Liquid water
B. Water vapour
C. Minerals
D. Food

Correct Answer: B
Explanation: Water is lost in vapour form from aerial parts.

Q27. Maximum transpiration occurs through:
A. Cuticle
B. Lenticels
C. Stomata
D. Roots

Correct Answer: C
Explanation: Stomata are the major route of water loss.

Q28. Transpiration pull helps in:
A. Food transport
B. Ascent of sap
C. Photosynthesis
D. Respiration

Correct Answer: B
Explanation: Transpiration creates negative pressure.

Q29. Transpiration is highest during:
A. Night
B. Early morning
C. Daytime
D. Rainy season

Correct Answer: C
Explanation: Stomata remain open during daylight.

Q30. High humidity causes transpiration to:
A. Increase
B. Stop
C. Decrease
D. Remain same

Correct Answer: C
Explanation: Diffusion gradient is reduced.

Q31. Cooling effect of plants is due to:
A. Respiration
B. Photosynthesis
C. Transpiration
D. Diffusion

Correct Answer: C
Explanation: Evaporation absorbs heat energy.

Q32. Which is an internal factor affecting transpiration?
A. Wind
B. Humidity
C. Leaf area
D. Temperature

Correct Answer: C
Explanation: Leaf structure influences water loss.

Q33. Why is transpiration called necessary evil?
A. Causes death
B. Causes mineral loss
C. Causes water loss but essential
D. Stops photosynthesis

Correct Answer: C
Explanation: Though water is lost, it aids transport and cooling.

Q34. Lenticular transpiration occurs in:
A. Leaves
B. Roots
C. Woody stems
D. Flowers

Correct Answer: C
Explanation: Lenticels are present in woody stems.

Q35. Wind increases transpiration by:
A. Closing stomata
B. Increasing humidity
C. Removing moist air
D. Decreasing temperature

Correct Answer: C
Explanation: Maintains steep diffusion gradient.

Q36. Transpiration mainly occurs from:
A. Underground parts
B. Aerial parts
C. Roots only
D. Xylem

Correct Answer: B
Explanation: Leaves and stems lose water vapour.

Q37. Which transpiration continues at night?
A. Stomatal
B. Cuticular
C. Lenticular
D. Both B and C

Correct Answer: D
Explanation: Cuticle and lenticels are not regulated by light.

Q38. Transpiration stream refers to movement of:
A. Food in phloem
B. Water in xylem
C. Gases in leaves
D. Minerals in phloem

Correct Answer: B
Explanation: Continuous upward water movement.

Section D: Water & Mineral Transport (MCQs 39–50)

Q39. Tissue responsible for water transport is:
A. Phloem
B. Cortex
C. Xylem
D. Cambium

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

Q40. Ascent of sap occurs through:
A. Phloem
B. Cortex
C. Xylem
D. Epidermis

Correct Answer: C

Q41. Most accepted theory of ascent of sap is:
A. Root pressure theory
B. Capillarity theory
C. Diffusion theory
D. Cohesion–tension theory

Correct Answer: D

Q42. Cohesion refers to attraction between:
A. Water and walls
B. Solutes
C. Water molecules
D. Xylem cells

Correct Answer: C

Q43. Adhesion helps water by:
A. Breaking column
B. Sticking to xylem walls
C. Increasing diffusion
D. Decreasing pressure

Correct Answer: B

Q44. Root pressure is generated due to:
A. Transpiration
B. Osmotic ion uptake
C. Diffusion
D. Photosynthesis

Correct Answer: B

Q45. Root pressure is effective mainly in:
A. Tall trees
B. Small plants
C. Desert plants
D. Aquatic plants

Correct Answer: B

Q46. Minerals are absorbed by roots mainly as:
A. Molecules
B. Salts
C. Ions
D. Gases

Correct Answer: C

Q47. Active transport requires:
A. Diffusion
B. ATP
C. Water potential
D. Pressure

Correct Answer: B

Q48. Apoplast pathway involves movement through:
A. Cytoplasm
B. Cell walls
C. Plasmodesmata
D. Vacuoles

Correct Answer: B

Q49. Symplast pathway involves movement through:
A. Cell walls
B. Intercellular spaces
C. Cytoplasm
D. Xylem vessels

Correct Answer: C

Q50. Minerals reach leaves mainly due to:
A. Diffusion
B. Root pressure only
C. Transpiration pull
D. Osmosis only

Correct Answer: C
Explanation: Minerals move with water in transpiration stream.

Best Suited For

• CBSE Class 11 Annual Exams
• NCERT-based MCQ practice
• Concept strengthening & revision

Targeting Exams

• CBSE Class 11 Biology Annual Examination

• CBSE School-Based Assessments

• NCERT Chapter-wise Practice Tests

• Unit Tests & Term Examinations

• Foundation preparation for Class 12 Biology

Related Keyphrases

• Transport in Plants MCQs with answers

• Class 11 Biology Transport in Plants questions

• NCERT Transport in Plants MCQ test

• CBSE Class 11 Plant Physiology MCQs

• Diffusion Osmosis Transpiration MCQs

• Water and mineral transport MCQs Class 11

• Biology Chapter 11 MCQs NCERT