Lesson T1.3.4

T1.3.4 The human digestive system Quiz: KS3 Biology, Unit 1

20 questions

Written by Revision Ninja · Last reviewed 11 October 2026

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Lesson T1.3.4, The human digestive system: 20 multiple choice questions for the KS3 Biology (National Curriculum), Unit 1: Structure and function of living organisms, written with Revision Ninja.

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The 20 questions

  1. Where in the human body does mechanical digestion begin?

    • Mouth
    • Small intestine
    • Stomach
    • Oesophagus

  2. Which enzyme starts the digestion of carbohydrates in the mouth?

    • Lipase
    • Pepsin
    • Amylase
    • Protease

  3. Which organ produces hydrochloric acid and the enzyme pepsin?

    • The liver
    • The pancreas
    • The stomach
    • The small intestine

  4. Which enzyme breaks down proteins into amino acids?

    • Amylase
    • Lipase
    • Bile
    • Protease

  5. Which enzyme breaks down fats into fatty acids and glycerol?

    • Pepsin
    • Lipase
    • Protease
    • Amylase

  6. Where is bile produced?

    • The stomach
    • The large intestine
    • The pancreas
    • The liver

  7. What is the primary role of bile in digestion?

    • Digesting proteins
    • Killing bacteria
    • Emulsifying fats
    • Absorbing water

  8. Which structure gives the small intestine a large surface area for absorption?

    • The oesophagus
    • Villi
    • The anus
    • The gall bladder

  9. Why is the wall of a small intestine villus very thin?

    • Chewing food
    • Fast diffusion
    • Producing acid
    • Releasing bile

  10. What is the main function of the large intestine?

    • Absorbing water
    • Absorbing protein
    • Producing bile
    • Digesting starch

  11. What name is given to the tube connecting the mouth and stomach?

    • Trachea
    • Oesophagus
    • Bronchus
    • Ureter

  12. Which organ stores bile before it enters the small intestine?

    • The stomach
    • The kidney
    • The pancreas
    • The gall bladder

  13. Which organ produces amylase, protease and lipase?

    • The liver
    • The pancreas
    • The large intestine
    • The stomach

  14. What role do digestive enzymes play in the body?

    • Nerve signals
    • Physical barriers
    • Biological catalysts
    • Energy stores

  15. Why does the human stomach contain strong acid?

    • Digest fibre
    • Absorb glucose
    • Emulsify lipids
    • Activate pepsin

  16. Which sequence correctly traces food through the digestive tract?

    • Liver to oesophagus
    • Rectum to stomach
    • Mouth to stomach
    • Stomach to mouth

  17. Which organ in the human body produces bile?

    • Liver
    • Stomach
    • Gall bladder
    • Pancreas

  18. Which part of the digestive system absorbs most of the digested food into the blood?

    • The large intestine
    • The mouth
    • The stomach
    • The small intestine

  19. Why does the enzyme pepsin function effectively in the stomach?

    • Alkaline conditions
    • Neutral pH
    • Acidic conditions
    • High temperature

  20. Which organ releases digestive enzymes into the small intestine?

    • The pancreas
    • The oesophagus
    • The liver
    • The stomach

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