Digestive System Quiz

Name:

Date:

Part 1: Knowledge and Understanding

Instructions: Choose the best answer for Questions 1–3. Complete the matching and sequencing activities. Total: 11 marks.

1. Where does most chemical digestion and nutrient absorption take place? (1 mark)

Mouth

Stomach

Small intestine

Large intestine

2. Which organ produces bile? (1 mark)

Liver

Pancreas

Stomach

Small intestine

3. What is the main role of the large intestine? (1 mark)

Absorb water from undigested material

Produce saliva

Pump blood around the body

Absorb most glucose into the blood

4. Match each organ with its main function. Write the correct letter beside each organ. (4 marks)

1. Mouth ______

2. Oesophagus ______

3. Stomach ______

4. Small intestine ______

A. Moves food to the stomach by muscular contractions

B. Absorbs digested nutrients into the blood

C. Chews food and mixes it with saliva

D. Churns food and begins protein digestion

5. Number these stages from 1 to 5 to show the path food takes through the digestive system. (4 marks)

______ Small intestine

______ Mouth

______ Large intestine

______ Oesophagus

______ Stomach

Part 2: Short Answer and Application

Answer in complete sentences where appropriate. Total: 14 marks.

6. Explain the difference between mechanical digestion and chemical digestion. Give one example of each. (2 marks)

7. What is the role of digestive enzymes? Name one enzyme and state what type of food molecule it helps digest. (2 marks)

8. Describe two functions of bile in digestion. (2 marks)

9. Explain how the structure of villi helps the small intestine absorb nutrients efficiently. (3 marks)

10. What happens to material in the large intestine, and why is this important? (2 marks)

11. Higher-order application: A person has damaged villi in their small intestine. Predict how this could affect their body and explain why. (3 marks)

Teacher Answer Key and Mark Allocation

1. Small intestine. (1)

2. Liver. (1)

3. Absorb water from undigested material. (1)

4. 1–C, 2–A, 3–D, 4–B. (1 mark each)

5. Small intestine – 4; Mouth – 1; Large intestine – 5; Oesophagus – 2; Stomach – 3. (1 mark for each correct position)

6. (2 marks) Mechanical digestion physically breaks food into smaller pieces, for example chewing or stomach churning. Chemical digestion uses enzymes or other chemicals to break large food molecules into smaller soluble molecules. Award 1 mark for each correctly explained type and example.

7. (2 marks) Enzymes speed up the chemical digestion of food molecules. Examples include amylase digesting starch or protease digesting proteins. Award 1 mark for the role of enzymes and 1 mark for a correct enzyme and food molecule.

8. (2 marks) Bile neutralises acidic food from the stomach and emulsifies fats into smaller droplets, increasing the surface area for lipase to act. Award 1 mark for each function.

9. (3 marks) Villi provide a large surface area; they have a thin lining for a short diffusion distance; and they contain many blood capillaries to carry absorbed nutrients away. Award 1 mark for each valid structural feature linked to absorption.

10. (2 marks) The large intestine absorbs water and some salts from undigested material. This helps maintain the body's water balance and forms faeces. Award 1 mark for absorption of water and 1 mark for its importance.

11. (3 marks) Damaged villi reduce the surface area available for absorption, so fewer nutrients enter the blood. This could lead to nutrient deficiencies, weight loss, tiredness or poor growth. Award 1 mark for reduced absorption, 1 mark for linking this to damaged or fewer villi, and 1 mark for a valid effect on the body.

Total: 25 marks