Y9 Review #1

1. In which organelle does photosynthesis primarily occur?

• Mitochondrion
• Ribosome
• Chloroplast
• Nucleus

2. What is the correct summary word equation for photosynthesis?

• Glucose + Oxygen → Carbon dioxide + Water
• Carbon dioxide + Water → Glucose + Oxygen
• Carbon dioxide + Glucose → Water + Oxygen
• Water + Glucose → Oxygen + Carbon dioxide

3. Which molecule absorbs light energy for photosynthesis?

• Glucose
• Water
• Carbon dioxide
• Chlorophyll

5. What is the primary purpose of the light-dependent reactions in photosynthesis?

• To produce glucose from carbon dioxide
• To capture and convert light energy into chemical energy (ATP and NADPH)
• To release oxygen into the atmosphere
• To absorb water through the roots

6. The oxygen gas produced during photosynthesis comes from the splitting of which molecule?

• Glucose (C₆H₁₂O₆)
• Carbon dioxide (CO₂)
• Water (H₂O)
• ATP

9. How do plants typically store the excess glucose they produce?

• As protein
• As cellulose
• As fat
• As starch

10. Why do most leaves appear green to the human eye?

• They absorb green light
• They reflect green light
• They produce a green-coloured gas
• The cell walls are naturally green

11. Which factor is LEAST likely to be a limiting factor for photosynthesis in a tropical rainforest?

• Light intensity
• Temperature
• Carbon dioxide concentration
• Water availability

12. If a plant is kept in ideal conditions for temperature and CO₂, but very dim light, what is the limiting factor?

• Temperature
• Water availability
• Light intensity
• CO₂ concentration

13. What typically happens to the rate of photosynthesis if the temperature increases far beyond its optimum (e.g., to 50°C)?

• It increases rapidly
• It stays the same
• It decreases as enzymes denature
• It stops instantly