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Class 10 Science — Life processes

Trace food through the human gut and blood round the double circulation, say where each digestive juice acts, and explain how a plant moves water up and sugar down.

Name: ________________________

  1. 1.Sort each of these by where along the gut it does its work.

    Groups: Mouth · Stomach · Small intestine

    • Trypsin
    • Pepsin
    • Hydrochloric acid
    • Lipase
    • Salivary amylase
    • Bile juice

  2. 2.A fish opens and closes its mouth far more often in a minute than you breathe. Why?

    • a) There is much less oxygen dissolved in water than there is in air
    • b) A fish needs more oxygen than a human being does
    • c) Water is heavier than air and moves more slowly
    • d) A fish has smaller lungs than a human being

  3. 3.Blood goes round and round, so pick a place to begin: starting from "The right atrium", put the stages of one full circuit in order.

    • The left ventricle
    • The right ventricle
    • The right atrium
    • The rest of the body
    • The left atrium
    • The lungs

  4. 4.Which pair of statements matches the two conducting tissues of a plant?

    • a) Xylem carries water and sugar; phloem carries minerals
    • b) Xylem carries sugar down; phloem carries water up
    • c) Xylem carries water and minerals up; phloem carries the products of photosynthesis both ways
    • d) Both carry water, xylem by day and phloem by night

  5. 5.Fat arrives in the small intestine as large globules. What does bile do about it?

    • a) It absorbs the fat into the blood
    • b) It breaks the globules into smaller ones so enzymes can reach more of the fat
    • c) It stops the fat from reaching the pancreas
    • d) It digests the fat completely into fatty acids and glycerol

  6. 6.Put the parts of the alimentary canal in the order food passes through them, starting with "Mouth".

    • Oesophagus
    • Large intestine
    • Mouth
    • Stomach
    • Small intestine
    • Anus

  7. 7.Match each stage in the break-down of glucose to what it produces.

    • The first step, taken in the cytoplasm
    • Fermentation in yeast
    • Break-down of pyruvate in the mitochondria
    • A muscle cell short of oxygen
    • Ethanol and carbon dioxide
    • Carbon dioxide and water
    • Pyruvate
    • Lactic acid

  8. 8.Why does a herbivore have a longer small intestine than a carnivore of the same size?

    • a) A longer intestine absorbs more water
    • b) Herbivores eat less often
    • c) Plants contain more protein than meat does
    • d) Cellulose from grass takes longer to digest than meat does

Answer key — Class 10 Science — Life processes

  1. 1. Salivary amylase → Mouth; Hydrochloric acid → Stomach; Pepsin → Stomach; Bile juice → Small intestine; Trypsin → Small intestine; Lipase → Small intestine
  2. 2. a) There is much less oxygen dissolved in water than there is in air
  3. 3. 1. The right atrium 2. The right ventricle 3. The lungs 4. The left atrium 5. The left ventricle 6. The rest of the body
  4. 4. c) Xylem carries water and minerals up; phloem carries the products of photosynthesis both ways
  5. 5. b) It breaks the globules into smaller ones so enzymes can reach more of the fat
  6. 6. 1. Mouth 2. Oesophagus 3. Stomach 4. Small intestine 5. Large intestine 6. Anus
  7. 7. The first step, taken in the cytoplasm → Pyruvate; Fermentation in yeast → Ethanol and carbon dioxide; Break-down of pyruvate in the mitochondria → Carbon dioxide and water; A muscle cell short of oxygen → Lactic acid
  8. 8. d) Cellulose from grass takes longer to digest than meat does