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NEET Photosynthesis in Higher Plants: 5 practice MCQs

By the PrepMatic team · Updated 9 Oct 2026 · 3 min read

Photosynthesis in Higher Plants is a Class 11 Biology chapter in which pigments, light reactions, the Calvin cycle and C4 plants appear again and again in NEET papers. The five MCQs below test the site of the Calvin cycle, the first product of C4 fixation, photorespiration, the energy cost of making glucose and the reaction centre of photosystem I.

What this chapter covers in the NEET syllabus

Photosynthesis is part of the NMC unit Plant Physiology, taught as the Class 11 NCERT chapter Photosynthesis in Higher Plants. The topics are:

• Early experiments, the site of photosynthesis and the photosynthetic pigments.
• The light reaction: photosystems I and II, the Z scheme, and cyclic and non-cyclic photophosphorylation.
• Chemiosmotic hypothesis for the synthesis of ATP.
• The Calvin cycle, the C3 pathway, and the C4 pathway.
• Photorespiration.
• Factors affecting photosynthesis, including light, CO₂ and temperature, and the law of limiting factors.

Five practice MCQs on Photosynthesis

Question 1

The Calvin cycle (dark reaction) takes place in the:

• A. thylakoid lumen
• B. stroma of the chloroplast
• C. outer membrane of the chloroplast
• D. cytoplasm

Question 2

In C4 plants, the first stable product of CO₂ fixation is:

• A. 3-phosphoglyceric acid
• B. ribulose bisphosphate
• C. oxaloacetic acid
• D. pyruvic acid

Question 3

The oxygenase activity of RuBisCO leads to:

• A. photorespiration
• B. glycolysis
• C. the Krebs cycle
• D. cyclic photophosphorylation

Question 4

The number of ATP and NADPH molecules needed in the Calvin cycle to synthesise one molecule of glucose (six CO₂ fixed) is:

• A. 6 ATP and 6 NADPH
• B. 12 ATP and 18 NADPH
• C. 36 ATP and 12 NADPH
• D. 18 ATP and 12 NADPH

Question 5

The reaction centre of photosystem I has its absorption peak at:

• A. 680 nm
• B. 700 nm
• C. 450 nm
• D. 560 nm

Answers and explanations

1. B. The light reaction occurs in the thylakoid membranes (grana), where pigments and electron carriers sit. The Calvin cycle enzymes are in the stroma, which also holds the starch grains and the chloroplast DNA.
2. C. C4 plants first fix CO₂ into a four-carbon acid, oxaloacetic acid (OAA), in mesophyll cells using PEP carboxylase. In C3 plants the first stable product is the three-carbon 3-PGA, formed by RuBisCO.
3. A. RuBisCO can also bind O₂ in place of CO₂, which starts photorespiration in C3 plants. The process uses energy and releases CO₂ without making sugar or ATP. C4 plants largely avoid it because CO₂ is concentrated around RuBisCO in the bundle sheath cells.
4. D. Each CO₂ fixed needs 3 ATP and 2 NADPH, so six CO₂ need 18 ATP and 12 NADPH to make one glucose. Option B swaps the ratio: the cycle needs fewer NADPH than ATP, not more.
5. B. The reaction centre of photosystem I is chlorophyll a P700, absorbing at 700 nm. Photosystem II has P680. Both sit with antennae of other pigment molecules.

How to prepare Photosynthesis

• Learn the two reactions as a flow. Light energy gives ATP and NADPH in the thylakoid, and these feed carbon fixation in the stroma. Draw the Z scheme once with the order of carriers: PS II, plastoquinone, cytochrome b6f, plastocyanin, PS I, ferredoxin, NADP reductase.
• Know where water splits and where protons build up. Photolysis happens on the lumen side of PS II, and ATP synthase uses the proton gradient across the thylakoid membrane. These are favourite statement questions.
• Compare C3 and C4 in a table: the first product, the enzyme (RuBisCO versus PEP carboxylase), cell types (Kranz anatomy), photorespiration, optimum temperature and examples (maize, sugarcane). Practise drawing the Hatch-Slack pathway.
• Memorise the Calvin cycle stages: carboxylation, reduction and regeneration, with the number of ATP and NADPH in each.
• Understand the factors. Blackman's law of limiting factors, and why light saturation occurs at lower intensity than full sunlight for C3 plants.

Revise this chapter alongside Respiration in Plants, since their questions often compare the two. The NEET Biology preparation guide shows how to schedule them, and the NEET syllabus lists the units.

Take a full Photosynthesis test on PrepMatic

Photosynthesis and respiration are often revised together, so you can set up a longer Biology test on PrepMatic by building a custom mock: choose the subject, the number of questions, the duration and the difficulty. A standard topic test is about 15 questions in 30 minutes. Both use NEET's negative marking, and the practice hub has more chapters.

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