1. Define digestion and name the three main types of digestive enzymes.
Answer
Digestion is the breakdown of large, insoluble food molecules into smaller, soluble molecules. The main digestive enzymes are carbohydrase, protease and lipase.
2. Explain how stents are used to treat coronary heart disease.
Answer
A stent is a wire mesh that can be inserted into a coronary artery to keep it open so more blood can flow through.
3. Describe how cell division can result in cancer.
Answer
Cancer is the result of changes in cells that lead to uncontrolled growth and division. Malignant tumours are formed and they can spread from one part of the body to another.
4. Amylase (carbohydrase), lipase and protease are digestive enzymes. Show the substrates of amylase and protease, and the products of lipase and protease.
Answer
The substrate of amylase is starch and the substrate of protease is protein. The products of lipase are are fatty acids and glycerol, while the products of protease are amino acids.
5. The figure below shows the human breathing system. Name the parts labelled A–E.
Answer
6. Give the functions of the left and right ventricles of the heart.
Answer
Left ventricle pumps blood around the body. Right ventricle pumps blood to the lungs where gas exchange takes place.
7. Describe some risks associated with heart or heart-and-lung transplants.
Answer
The transplant may be rejected, patient needs to take immunosuppressant drugs to prevent rejection, waiting lists for donor can be very long, there is a risk of (viral) infection from the donor heart or from the operation.
8. Which substances are not transported by blood plasma ?
a) oxygen and lipids b) lactic acid and mineral ions c) vitamins and hormones d) glucose and amino acids
Answer
a) oxygen and lipids
9. Name a disease that obesity is not a risk factor for
a) cardiovascular disease b) cancer c) asthma d) type 2 diabetes
Answer
c) asthma
10. Carcinogens are chemicals or agents that can cause cancer by damaging DNA. Which of the following is not an example of a carcinogen ?
a) X–rays b) some UV light c) alcohol d) asbestos
Answer
c) alcohol