Exam practice
Exam questions
Write your answer. Then open the mark scheme and tick each point you made.
- Question 1 of 122 marks
State what the body uses carbohydrate for, and what it uses protein for.
Mark scheme
- Carbohydrate: a source of energy
- Protein: growth and repair (accept: building new tissue)
- Question 2 of 122 marks
Name the mineral needed for red blood cells, and the mineral needed for strong teeth and bones.
Mark scheme
- Red blood cells: iron
- Teeth and bones: calcium
- Question 3 of 122 marks
Explain what is meant by a balanced diet.
Mark scheme
- It contains carbohydrates, lipids, proteins, vitamins, minerals, fibre and water (accept: all the nutrients the body needs)
- In the right amounts (accept: not too much and not too little of each)
- Question 4 of 122 marks
A breakfast cereal has 1600 kJ of energy in 100 g. Calculate the energy in a 25 g serving.
Mark scheme
- 1600 ÷ 4 (accept: 1600 × 25 ÷ 100)
- 400 kJ
- Question 5 of 122 marks
Give two reasons why one person may need more energy from food each day than another.
Mark scheme
- Any one from: they are more active; they are still growing; they have a bigger body
- A second, different reason from the same list (accept: a difference in age, if its effect is explained)
- Question 6 of 122 marks
Name the deficiency disease caused by too little vitamin C, and the one caused by too little iron.
Mark scheme
- Vitamin C: scurvy
- Iron: anaemia
- Question 7 of 122 marks
Describe two things that happen to food in the stomach.
Mark scheme
- It is churned (mixed) with acidic juices
- The acid kills microorganisms
- The digestion of protein starts
- Question 8 of 122 marks
State where in the gut digestion is completed, and where water is absorbed from undigested food.
Mark scheme
- Digestion is completed in the small intestine
- Water is absorbed in the large intestine
- Question 9 of 122 marks
Explain why starch has to be digested before the body can use it.
Mark scheme
- Starch molecules are too big to pass through the wall of the small intestine (accept: too big to be absorbed into the blood)
- Digestion breaks them into small (sugar) molecules, which can pass into the blood
- Question 10 of 121 mark
Enzymes are biological catalysts. State what a catalyst does.
Mark scheme
- It speeds up a chemical reaction (accept: it speeds up digestion)
- Question 11 of 122 marks
Explain how villi help the small intestine to absorb food quickly.
Mark scheme
- They give the small intestine a large surface area
- So more food molecules can pass into the blood at the same time (accept: their thin walls give a short distance to the blood; their blood supply carries the food away)
- Question 12 of 121 mark
Give one way in which gut bacteria help the body.
Mark scheme
- Any one from: they help to break down food (such as fibre); they make some vitamins; they make it hard for harmful microorganisms to grow