Plants and Photosynthesis Quiz

Grade 3 · Science · Quiz

Test what you know about how plants make food through photosynthesis.

Questions

1. Where does most photosynthesis take place in a plant?

   1. Roots
   2. Stem
   3. Leaves
   4. Flowers
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   Answer: Leaves

   Leaves are flat and wide to capture maximum sunlight and are packed with chloroplasts where photosynthesis happens.

2. Plants need sunlight to perform photosynthesis.

   Show answer

   Answer: True

   Sunlight provides the energy that drives the photosynthesis reaction. Without light, plants cannot convert water and CO2 into glucose.

3. Plants absorb water through their ___.

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   Answer: roots

   Roots absorb water from the soil. The water travels up through xylem tubes in the stem and into the leaves.

4. What do plants release through their stomata during photosynthesis?

   1. Carbon dioxide
   2. Nitrogen
   3. Oxygen
   4. Water only
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   Answer: Oxygen

   Oxygen is a byproduct released by plants. This is why forests and plants are so important for keeping Earth's air breathable.

5. Plants can make food in the dark as long as they have water.

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   Answer: False

   Plants must have light for photosynthesis. Without sunlight, they cannot make food no matter how much water they have. They will use up stored energy and eventually die.

6. What is the name for tiny pores on a leaf that let gases in and out?

   1. Chloroplasts
   2. Stomata
   3. Xylem
   4. Veins
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   Answer: Stomata

   Stomata are microscopic openings, usually on the underside of leaves. They open to let CO2 in and release O2 and water vapor out.

7. The structure inside a plant cell where photosynthesis occurs is the ___.

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   Answer: chloroplast

   Chloroplasts contain chlorophyll and are the actual locations where light energy is captured and used to build glucose molecules.

8. Carbon dioxide is a product that plants release during photosynthesis.

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   Answer: False

   Plants take IN carbon dioxide and release oxygen. Carbon dioxide is a raw material for photosynthesis, not a product of it.

9. What color is chlorophyll?

   1. Yellow
   2. Blue
   3. Red
   4. Green
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   Answer: Green

   Chlorophyll is green because it absorbs red and blue light for energy but reflects green light back to our eyes.

10. Which of these is NOT needed for photosynthesis?

    1. Water
    2. Sunlight
    3. Oxygen
    4. Carbon dioxide
    Show answer

    Answer: Oxygen

    Oxygen is actually a product of photosynthesis, not something needed for it. Water, sunlight, and carbon dioxide are the three ingredients plants need.

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