Lesson T2.1.3

T2.1.3 Adaptations of leaves for photosynthesis Quiz: KS3 Biology, Unit 2

20 questions

Written by Revision Ninja · Last reviewed 11 October 2026

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Lesson T2.1.3, Adaptations of leaves for photosynthesis: 20 multiple choice questions for the KS3 Biology (National Curriculum), Unit 2: Material cycles and energy, written with Revision Ninja.

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The 20 questions

  1. Why are leaves broad and flat?

    • To reduce the amount of gas exchange with the air outside the leaf
    • To make them easier to dry out quickly in the wind and sun
    • To store large amounts of starch in the leaf tissue for winter
    • To give a large surface area for absorbing light

  2. Why are leaves thin?

    • So that gases and light can reach the cells quickly
    • So that they can store water for long periods
    • So that the leaf is less able to make glucose
    • So that they can produce more chlorophyll in the dark

  3. Where is most chlorophyll found in a leaf?

    • In the lower epidermis only, close to the guard cells there
    • In the root hairs that absorb water from the soil
    • In the palisade cells near the upper surface
    • In the xylem vessels that carry water up the stem

  4. Where are most stomata found on a leaf?

    • On the stem only
    • On the lower surface
    • On the roots only
    • On the upper surface only

  5. What is the function of stomata?

    • To allow gas exchange, letting carbon dioxide in and oxygen out
    • To make chlorophyll in the dark when light is unavailable
    • To transport sugars around the whole plant to growing parts
    • To absorb water from the soil around the roots of the whole plant

  6. What do guard cells do?

    • They open and close the stomata
    • They absorb water from the roots
    • They transport sugar to the flower
    • They make glucose from light

  7. Why does a leaf's waxy cuticle help the plant?

    • It stores extra glucose for the plant to use later
    • It absorbs more light for photosynthesis in the leaf
    • It reduces water loss from the leaf surface
    • It releases oxygen through the surface of the leaf

  8. What is the job of xylem vessels in a leaf?

    • To make chlorophyll in the chloroplasts of the leaf
    • To carry sugars away from the leaf to the roots
    • To allow carbon dioxide to diffuse in through the surface
    • To carry water and minerals to the leaf

  9. What do phloem tubes carry in a leaf?

    • Carbon dioxide to the palisade cells in the leaf for photosynthesis
    • Water from the soil that moves up to the stomata of the leaf
    • Sugars made by photosynthesis to other parts of the plant
    • Oxygen made in the leaves that travels down to the roots of the plant

  10. Why do the leaf veins matter for photosynthesis?

    • They carry water in and sugars out of the leaf
    • They stop water loss completely from the whole leaf surface
    • They produce oxygen directly from the sun's light energy
    • They make the leaf cells divide faster during the day

  11. What is the upper epidermis of a leaf usually like?

    • Transparent, so light reaches the palisade cells
    • Full of chloroplasts that absorb all the light falling on it
    • Full of stomata to take in carbon dioxide from the open air
    • Filled with water that the leaf stores for use in dry weather

  12. Why do spongy mesophyll cells have large air spaces?

    • To absorb minerals from the soil into the leaf tissue
    • To let gases diffuse easily to and from the stomata
    • To trap sunlight at the leaf edge where it is strongest
    • To store water for the whole plant during long dry spells

  13. A plant is grown in low light. Which leaf change is most likely?

    • Leaves that have no stomata at all on either surface
    • Smaller leaves with fewer chloroplasts in each of its cells
    • Leaves that lose all their chlorophyll and turn colourless
    • Larger leaves with more chlorophyll to catch light

  14. Why do cacti have spines instead of broad leaves?

    • Spines store glucose for the plant to use during winter
    • Spines reduce water loss in hot, dry conditions
    • Spines absorb more sunlight for photosynthesis in the stem
    • Spines release more oxygen into the air around the plant

  15. Which feature of a leaf helps it absorb carbon dioxide efficiently?

    • A dense layer of xylem in the upper epidermis
    • Many stomata and a large internal surface area
    • A thick waxy cuticle on both surfaces of the leaf
    • Few stomata with a small total surface area for gases

  16. Why are leaves often green?

    • Chlorophyll absorbs green light and reflects red light instead
    • Stomata reflect green light from the leaf surface to the eye
    • Chlorophyll reflects green light to our eyes
    • Starch in the leaf reflects all colours of light equally

  17. On a hot, dry day, what do guard cells usually do?

    • Open the stomata wider to lose more water
    • Move the leaf to face the sun directly
    • Close the stomata to reduce water loss
    • Stop the chloroplasts from working

  18. Why is a leaf structure described as adapted for photosynthesis?

    • Its shape stops it from absorbing much light in bright sunshine
    • It is designed to attract insects for pollination of the flower
    • Its shape and cells help it absorb light and exchange gases
    • It is built mainly to store water for the whole plant during drought

  19. What is the most likely effect of a blocked stoma on a leaf cell?

    • The leaf makes extra starch in the dark to store for later use
    • More carbon dioxide is made inside the cell itself by respiration
    • Oxygen is absorbed directly from the cell wall into the cell's sap
    • Less carbon dioxide can reach the cell, so photosynthesis slows

  20. Why do leaves need a large internal surface area?

    • To make the leaf heavier so that it stays firmly on the plant
    • To block sunlight from reaching the palisade layer of cells
    • To let more carbon dioxide and water reach the cells
    • To prevent gases from moving in and out of the whole leaf

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