Photosynthesis questions

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Photosynthesis question collection

Review Photosynthesis questions for Biology, with correct answers shown and coverage across reactants and products of photosynthesis; chloroplasts and light absorption; limiting factors.

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Question 1

What is photosynthesis?
  1. A process where plants use light energy to make glucose
  2. A process where plants break down glucose to release energy
  3. A process where plants absorb oxygen through roots
  4. A process where plants convert proteins into minerals

Question 2

Which gas is taken in by leaves for photosynthesis?
  1. Carbon dioxide
  2. Oxygen
  3. Nitrogen
  4. Hydrogen

Question 3

Which substance is produced by photosynthesis and used as plant food?
  1. Glucose
  2. Starch
  3. Cellulose
  4. Chlorophyll

Question 4

Which gas is released by photosynthesis?
  1. Oxygen
  2. Carbon dioxide
  3. Methane
  4. Sulfur dioxide

Question 5

In which cell organelle does photosynthesis happen?
  1. Chloroplast
  2. Mitochondrion
  3. Nucleus
  4. Ribosome

Question 6

What is the role of chlorophyll?
  1. To absorb light energy
  2. To absorb mineral ions from soil
  3. To transport sugars in phloem
  4. To store oxygen in roots

Question 7

Which raw material for photosynthesis is absorbed from the soil?
  1. Water
  2. Glucose
  3. Oxygen
  4. Protein

Question 8

Which tissue transports water to leaves for photosynthesis?
  1. Xylem
  2. Phloem
  3. Epidermis
  4. Palisade layer

Question 9

Where does most photosynthesis occur in a leaf?
  1. Palisade mesophyll cells
  2. Lower epidermis
  3. Guard cells only
  4. Phloem vessels

Question 10

Why are many palisade cells near the top of a leaf?
  1. They receive more light
  2. They absorb most water directly from air
  3. They release carbon dioxide for respiration only
  4. They store all mineral ions permanently

Question 11

What is the function of stomata in photosynthesis?
  1. They allow carbon dioxide to enter the leaf
  2. They absorb water from the xylem
  3. They produce glucose directly
  4. They move sugars into the phloem

Question 12

What happens to photosynthesis rate if light intensity increases and no other factor is limiting?
  1. The rate increases
  2. The rate always decreases
  3. The rate stays at zero
  4. The rate is unchanged at all light levels

Question 13

If carbon dioxide concentration is very low, what happens to photosynthesis?
  1. The rate is limited and stays low
  2. The rate becomes maximum
  3. Photosynthesis changes into respiration
  4. Oxygen production doubles immediately

Question 14

What is a limiting factor?
  1. A factor in shortest supply that restricts the rate
  2. A factor that always increases the rate
  3. A factor that only affects respiration
  4. A factor that is never measurable

Question 15

Which pair are limiting factors for photosynthesis?
  1. Light intensity and carbon dioxide concentration
  2. Oxygen concentration and blood glucose
  3. Saliva pH and heart rate
  4. Nerve impulse speed and body temperature only

Question 16

Why can farmers add carbon dioxide in some greenhouses?
  1. To increase photosynthesis and crop yield
  2. To reduce light absorption by leaves
  3. To stop water transport in xylem
  4. To prevent all respiration in plants

Question 17

Which statement links photosynthesis and food chains correctly?
  1. Photosynthesis stores energy in biomass that consumers depend on
  2. Consumers make all biomass directly from sunlight
  3. Photosynthesis removes energy from ecosystems permanently
  4. Only decomposers use glucose made by plants

Question 18

What can plants make using glucose from photosynthesis?
  1. Starch for storage
  2. Mineral ions from water
  3. Oxygen as the main storage molecule
  4. Carbon dioxide for transport in phloem

Question 19

A plant is kept in darkness for \(24\,\mathrm{hours}\). What happens to photosynthesis?
  1. It stops because no light energy is available
  2. It doubles because chlorophyll is concentrated
  3. It continues at the same rate
  4. It changes into anaerobic respiration

Question 20

Which word equation is correct for photosynthesis?
  1. \(\text{Carbon dioxide} + \text{water} \to \text{glucose} + \text{oxygen}\)
  2. \(\text{Glucose} + \text{oxygen} \to \text{carbon dioxide} + \text{water}\)
  3. \(\text{Carbon dioxide} + \text{oxygen} \to \text{glucose} + \text{water}\)
  4. \(\text{Water} + \text{glucose} \to \text{carbon dioxide} + \text{oxygen}\)

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Review Photosynthesis questions for Biology, with correct answers shown and coverage across reactants and products of photosynthesis; chloroplasts and light absorption; limiting factors.

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