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Class 7 Science — Life processes in plants

Say what photosynthesis needs and what it gives back, read the experiment that proves each ingredient, and name the tubes that carry water up and food out.

Name: ________________________

Before you start

The parts of a plant, and what each one does with water and with food.

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  1. 1. Leaf
  2. 2. Stem
  3. 3. Roots

The leaf is where the food is made. Water and minerals go up from the roots through tubes called xylem, inside the stem. Food made in the leaves goes out through a second set of tubes called phloem, to wherever the plant needs it or stores it. Tiny pores in the leaf surface, the stomata, let gases in and out.

  1. 1.Three identical saplings are grown for two weeks: A in sunlight with water, B in sunlight without water, C in the dark with water. What do their fates show?

    • a) A plant needs sunlight and can manage without water
    • b) A plant needs both sunlight and water to grow
    • c) Neither sunlight nor water makes much difference over two weeks
    • d) A plant needs water and can manage without sunlight

  2. 2.Why does the chapter call leaves the food factories of a plant?

    • a) They are the part of the plant that animals eat most often
    • b) They take in the water and minerals the plant lives on
    • c) They are the primary site of photosynthesis, where the food is made
    • d) They store most of the plant's food until it is needed

  3. 3.The food a plant makes is first produced as a simple carbohydrate, which the plant later turns into starch for storage. What is that simple carbohydrate?

  4. 4.What is the name of the process by which a plant prepares its food in the presence of sunlight and chlorophyll?

  5. 5.Tiny pores on the surface of a leaf, seen under a microscope in a peel of its underside, let gases in and out. What are they called?

  6. 6.A potato slice turns blue-black with iodine, so it holds starch. Where was that starch made?

    • a) In the potato itself, which photosynthesises underground
    • b) In the leaves, and carried down to the potato through the phloem
    • c) In the stem, from water carried up by the xylem
    • d) In the roots, from minerals taken out of the soil

  7. 7.Which pair of ingredients does a plant draw from its surroundings to make food?

    • a) Carbon dioxide from the soil and oxygen from the air
    • b) Oxygen from the air and glucose from the soil
    • c) Carbon dioxide from the air and water from the soil
    • d) Starch from the soil and sunlight from the sky

  8. 8.Sort each substance by the part it plays in photosynthesis.

    Groups: Taken in by photosynthesis · Given out by photosynthesis

    • Water
    • Carbon dioxide
    • Oxygen
    • Glucose

Answer key — Class 7 Science — Life processes in plants

  1. 1. b) A plant needs both sunlight and water to grow
  2. 2. c) They are the primary site of photosynthesis, where the food is made
  3. 3. glucose
  4. 4. photosynthesis
  5. 5.
    • stomata
    • stoma
  6. 6. b) In the leaves, and carried down to the potato through the phloem
  7. 7. c) Carbon dioxide from the air and water from the soil
  8. 8. Carbon dioxide → Taken in by photosynthesis; Water → Taken in by photosynthesis; Glucose → Given out by photosynthesis; Oxygen → Given out by photosynthesis