Excretion

Question 1

(a)

(i)Define the term excretion (1)

(ii) List 5 other life processes (5)

Answer 1

(i) Excretion is the removal of metabolic waste from the body. (1)

(ii) Movement, Respiration, Sensitivity, Growth, Reproduction (5)

Question 2

Suggest why excess carbohydrates and lipids do not need to be excreted (2).

Answer 2

Its because carbohydrates can be stored as glycogen(1) and lipids are stored under the skin (1)

Question 3

Explain the importance of excreting carbon dioxide (2)

Answer 3

It’s important because it forms an acidic solution in the body which lowers the pH of the cells (1). This may reduce the activity of enzymes (1)

Question 4

Explain how the skin is able to carry out excretion (2).

Answer 4

The skin carries out excretion by excreting water and excess minerals like salt(1) through sweating.(1)