End Of Unit Questions

Question 1

What is the name of the red pigment in red blood cells?

Answer 1

Haemoglobin

Question 2

Which blood vessels carry blood away from the heart?

Answer 2

Arteries

Question 3

Why do blood only flow in one direction?

Answer 3

So it is efficient as it prevents backflow

Question 4

What is the function of white blood cells?

Answer 4

To defend the body against microorganisms

Question 5

What is transported by xylem?

Answer 5

Water and mineral ions

Question 6

What is transported by phloem?

Answer 6

Food, ex sugars

Question 7

Why do humans have a double circulation?

Answer 7

Blood must be circulated to the lungs to become oxygenated, which has to return to the heart to be pumped round the body

Question 8

Some patients are fitted with a stent in a coronary artery. Explain why.

Answer 8

The coronary arteries have been narrowed by fatty deposits and need to be reopened to make the circulation efficient

Question 9

Why has it been necessary to develop artificial hearts?

Answer 9

There are not enough donors

Question 10

If you were designing an artificial heart, what key features would you include?

Answer 10

• 2 pumps, one to pump blood to the lungs, another to pump blood to the rest of the body
• valves, to prevent backflow
• made of materials which do not cause an immune reaction

Question 11

Which type of blood vessel exchanges materials with the cells?

Answer 11

Capillaries