Year 8 Digestion and Nutrition Worksheet - Intermediate

Year 8 Digestion and Nutrition worksheet for Year 8 (Key Stage 3 / Year 7-9 (Ages 11-14)). Intermediate level science practice, aligned to the UK National Curriculum. Print-ready with answer key included.

Science•Key Stage 3 / Year 7-9 (Ages 11-14)•Human Bodyintermediate

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Digestion and Nutrition: The Body’s Fuel-to-Energy Journey

Year 8 Science | Ages 12–13 | Intermediate

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Instructions: Work through each activity and use scientific vocabulary in your answers. Show your reasoning where a question asks you to explain or calculate. The activities cover diet, digestion, deficiency diseases, lifestyle effects and gas exchange.

Food Groups and a Balanced Diet

Use your knowledge of nutrients and their functions. For each question, give a clear answer; include a reason where requested.

1. Which nutrient is the body's main source of energy for everyday activity?

2. Name the nutrient needed for growth and repair of body tissues.

3. A meal contains rice, grilled chicken, broccoli and olive oil. Name the main nutrient group supplied by the rice and the main nutrient group supplied by the chicken.

4. Explain why dietary fibre is important for a healthy digestive system.

5. Give one reason the body needs water as part of a balanced diet.

Follow the Food: Organs and Enzymes

Answer using the correct organ names and explain what enzymes do. For enzyme questions, name the food molecule being broken down and the smaller products formed.

1. Where does digestion begin, and what does chewing do to food?

2. Which organ produces bile, and which organ stores it before release?

3. Amylase breaks down starch. Name the smaller sugar produced.

4. Protease breaks down proteins. Name the smaller molecules produced.

5. In which organ are most digested nutrients absorbed into the blood?

Nutrients, Deficiencies and Evidence

Read the data and use it to identify the nutrient linked to each symptom. Then apply your knowledge of deficiency diseases. Nutrient values are fictional examples for this worksheet, not dietary recommendations.

Person	Daily vitamin C intake	Reported symptom
A	8 mg	bleeding gums
B	12 mg	slow wound healing
C	75 mg	no symptom reported

1. Which person reported no symptom, and what was their vitamin C intake?

2. Name the deficiency disease associated with a severe lack of vitamin C.

3. Name the deficiency disease caused by a lack of vitamin D in children.

4. Explain why the table alone cannot prove that low vitamin C caused the symptoms.

Lifestyle Choices and the Body

Choose the best answer for each question. Think about how drugs, alcohol and tobacco smoke affect health and body systems.

1. Which drug in tobacco smoke is strongly addictive?

2. Which organ is especially damaged by long-term heavy alcohol use?

3. Carbon monoxide in cigarette smoke reduces the blood’s ability to carry which gas?

4. Which statement best describes a drug?

Gas Exchange in the Lungs

Use the data and your knowledge of alveoli to answer. State the direction of gas movement clearly and explain how the alveoli are adapted for gas exchange.

Gas	Air entering alveoli	Air leaving alveoli
Oxygen	21%	16%
Carbon dioxide	0.04%	4%

1. Which gas has a lower percentage in the air leaving the alveoli?

2. In which direction does oxygen diffuse at the alveoli: from alveolar air into the blood, or from blood into alveolar air?

3. In which direction does carbon dioxide diffuse at the alveoli?

4. Give two features of alveoli that make gas exchange efficient.

Answer Key

Activity 1: 1. Carbohydrate; 2. Protein; 3. Rice: carbohydrate; chicken: protein; 4. Fibre adds bulk to food and helps it move through the gut, reducing constipation; 5. Any one: water is needed for chemical reactions, transporting substances, or regulating body temperature.

Activity 2: 1. Mouth; chewing breaks food into smaller pieces and increases its surface area; 2. Liver produces bile; gall bladder stores it; 3. Maltose; 4. Amino acids; 5. Small intestine.

Activity 3: 1. Person C; 75 mg; 2. Scurvy; 3. Rickets; 4. The table shows an association only; it has few people and does not control other factors or establish cause and effect.

Activity 4: 1. nicotine; 2. liver; 3. oxygen; 4. A substance that changes chemical processes in the body.

Activity 5: 1. Oxygen; 2. From alveolar air into the blood; 3. From the blood into alveolar air; 4. Any two: large surface area, thin walls, moist lining, or a rich blood supply.