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NEET MCQs On Photosynthesis in Higher Plants

DEEKSHA August 31, 2025

Photosynthesis in Higher Plants – NEET Notes + MCQs with Concept Explanations | Class 11th 

Ever ponder how plants, who do not consume food as humans do, are able to develop, endure, and even supply oxygen to the entire planet? The mechanism by which green plants absorb sunlight and transform it into chemical energy is called photosynthesis, and it holds the key to the solution.

We go into greater detail on the mechanism of photosynthesis, the discovery of light and dark reactions, the structure of pigments, and the Calvin cycle in Chapter 13: Photosynthesis in Higher Plants (Class 11 NCERT). Because the questions in this chapter are straightforward and concept-based, it is a scoring topic for NEET.

Let's simplify it for the benefit of the students and then assess ourselves using multiple-choice questions.

Photosynthesis in Higher Plants – NEET Notes + MCQs with Concept Explanations | Class 11th


Principles of Photosynthesis 

1. Photosynthesis Definition

The process by which green plants create glucose and oxygen from sunlight, CO₂, and water is known as photosynthesis.

2. The Pigments Used

  • The primary blue-green pigment is chlorophyll a.
  • The yellow-green accessory pigment is chlorophyll b.
  • Carotenoids absorb more light and shield chlorophyll.
  • The pigment xanthophylls is yellow.

3. The Hill Reaction, or Light Reaction

  • takes place in the thylakoid membrane. Important occasions:
  • Pigments' absorption of light
  • ATP production (photophosphorylation)
  • NADPH formation (reducing power)

4. Dark Reaction (Phase of Biosynthesis)

  • occurs in the chloroplast's stroma. requires ATP and NADPH from the light reaction but doesn't directly require light.
  • Calvin Cycle (C3 Cycle) is the pathway.
  • Carboxylation (CO₂ fixation)
  • Reduction (sugar formation)
  • Regeneration (regeneration of RuBP)

5. Pathways C3, C4, and CAM

  • C3 Plants: Most prevalent, only Calvin cycle (e.g., rice, wheat).
  • C4 plants, like sugarcane and maize, have a unique defense against photorespiration.
  • CAM plants, like cacti, fix CO₂ at night and photosynthesize during the day.

6. Elements That Impact Photosynthesis

  • The intensity of the light
  • Concentration of CO₂
  • The temperature
  • Availability of water

NEET MCQs with Concept Explanations

Q1. Photosynthesis takes place in which cell organelle?
A) Mitochondria
B) Chloroplast 
C) Nucleus
D) Ribosome
Answer  : B) Chloroplast
Concept Explanation: Chloroplast is the “kitchen of the cell” where photosynthesis occurs.

Q2. Which pigment is the reaction center in photosystem?
A) Chlorophyll b
B) Chlorophyll a 
C) Carotenoids
D) Xanthophyll
Answer  : B) Chlorophyll a 
Concept Explanation: Only chlorophyll a can directly take part in photochemical reactions.

Q3. Oxygen in photosynthesis comes from:
A) CO₂
B) H₂O 
C) Glucose
D) NADPH
Answer  : B) H₂O
Concept Explanation: Water splitting releases O₂. This was proven by Hill’s experiment.

Q4. The Calvin cycle occurs in:
A) Thylakoid
B) Stroma 
C) Cytoplasm
D) Outer membrane
Answer  : B) Stroma
Concept Explanation: Dark reactions (Calvin cycle) happen in the stroma of chloroplasts.

Q5. Which is the first stable product of the Calvin cycle?
A) RuBP
B) 3-PGA (Phosphoglyceric acid) 
C) Glucose
D) PEP
Answer  : B) 3-PGA (Phosphoglyceric acid) 
Concept Explanation: CO₂ combines with RuBP to form 3-PGA in C3 cycle.

Q6. Photorespiration occurs when RuBisCO fixes:
A) CO₂
B) O₂ 
C) H₂O
D) Glucose
Answer  : B) O₂
Concept Explanation: In presence of high O₂, RuBisCO binds O₂ instead of CO₂ → wastage of energy.

Q7. C4 plants are more efficient than C3 because:
A) They use more sunlight
B) They avoid photorespiration 
C) They absorb more water
D) They have more stomata
Answer  : B) They avoid photorespiration 
Concept Explanation: C4 pathway reduces photorespiration → higher yield.

Q8. CAM plants fix CO₂ during:
A) Day
B) Night 
C) Morning only
D) Evening only
Answer  : B) Night
Concept Explanation: CAM plants (like cactus) open stomata at night to reduce water loss.

Q9. Photophosphorylation refers to:
A) ATP breakdown
B) ATP synthesis using light 
C) NADPH oxidation
D) RuBP regeneration
Answer  : B) ATP synthesis using light
Concept Explanation: Light energy is used to make ATP in chloroplasts.

Q10. The main enzyme of Calvin cycle is:
A) ATP synthase
B) RuBisCO 
C) PEP carboxylase
D) Cytochrome
Answer  : B) RuBisCO
Concept Explanation: RuBisCO = Ribulose bisphosphate carboxylase-oxygenase, most abundant enzyme.

Q11. The site of photolysis of water is:
A) PS I
B) PS II 
C) Stroma
D) Mitochondria
Answer  : B) PS II
Concept Explanation: Water splitting → electrons for photosynthesis → occurs in Photosystem II.

Q12. Kranz anatomy is found in:
A) C3 plants
B) C4 plants 
C) CAM plants
D) Algae
Answer  : B) C4 plants
Concept Explanation: C4 plants have special leaf anatomy (Kranz = wreath-like).

Q13. In the Z-scheme of photosynthesis, the final acceptor of electrons is:
A) NADP⁺ 
B) ATP
C) O₂
D) FAD
Answer  : A) NADP⁺ 
Concept Explanation: Electrons move from water → PSII → PSI → NADP⁺ → NADPH.

Q14. The limiting factor for photosynthesis in field conditions is usually:
A) Light
B) CO₂ 
C) Temperature
D) Oxygen 
Answer  : B) CO₂ 
Concept Explanation: CO₂ concentration is often the major limiting factor.

Q15. In cyclic photophosphorylation, which product is formed?
A) ATP only 
B) ATP + NADPH
C) ATP + O₂
D) NADPH only
Answer  : A) ATP only
Concept Explanation: Cyclic photophosphorylation forms only ATP, no NADPH or O₂.

Finally, a brief recap

Light process (ATP + NADPH + O₂) + dark reaction (sugar production) = photosynthesis
The primary pigment is called chlorophyll a.
CAM and C4 pathways = efficiency-boosting adaptations.
MCQs from this chapter that are directly fact-based are frequently asked in NEET.

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