Q2. In non‑cyclic photophosphorylation, which component gets reduced last?
A. Ferredoxin
B. NADP⁺ C. Cytochrome b₆f D. Plastocyanin Correct: B

Q10. Final electron acceptor in non‑cyclic photophosphorylation:
A. O₂
B. NADP⁺ C. Ferredoxin D. PSII

Q9. CO₂ fixation in C₄ plants first occurs in:
A. Mesophyll
B. Bundle sheath C. Guard cells D. Phloem

Q12. Which pigment transfers electrons first in PSII?
A. P700
B. P680 C. Carotene D. Cytochrome c

Q13. ATP synthesis in chloroplast is driven by:
A. Electron loss
B. Proton gradient C. RuBP regeneration D. NADH oxidation

Q14. Which product increases when photorespiration rises?
A. PGA
B. OAA C. Phosphoglycolate D. NADPH

Q17. Main purpose of cyclic photophosphorylation:
A. NADPH formation
B. O₂ evolution C. Extra ATP generation D. CO₂ fixation

Deep Q1. If NADP⁺ becomes unavailable during light reactions, which event stops first?
A. Electron flow from PSI
B. ATP synthesis C. Water splitting D. Proton pumping

Deep Q2. If PSII is overexcited but electron transport is blocked, which increases first?
A. O₂
B. NADPH C. Heat dissipation D. ATP

Deep Q3. A C₄ plant shifted to low light shows first reduction in:
A. PEP regeneration
B. NADPH use C. Malate transport D. OAA formation

If CO₂ fixation increases but O₂ release remains constant, which process increased?
A. PSII activity
B. PSI activity C. Calvin cycle D. Photolysis

Hard Q1. In a chloroplast where PSI is functional but cytochrome b₆f is inhibited, which process stops first?
A. ATP synthesis
B. NADPH formation C. Electron flow to PSI D. CO₂ fixation

Hard Q2. A sudden rise in stromal pH indicates an increase in:
A. Photorespiration
B. Proton pumping C. Calvin cycle flux D. Cyclic photophosphorylation

Hard Q4. If PSI receives 700 nm light but NADP⁺ is absent, electrons will:
A. Flow to PSII
B. Accumulate in ferredoxin C. Stop flow entirely D. Increase O₂ production

Hard Q6. If ATP synthase rotates faster than usual, which consequence is most immediate?
A. Lumen pH rises
B. NADPH formation increases C. CO₂ fixation slows D. Electron transport speeds up