exam qs lqc 7a

Question 1

Describe how the following features assists in producing an efficient gaseous exchange system.
a) The lungs are composed of many alveoli. The alveoli are ventilated

Answer 1

brings oxygen to exchange system, maintains concentration gradient

Question 2

An amoeba is a single-celled organism that lives in water. Gas exchange in an amoeba occurs between the water and the cytoplasm. suggest how gas exchange occurs in an amoeba.

Answer 2

gas exchange occurs through the cell membrane, membrane is thin, oxygen enters cell from water, carbon dioxide leaves cell into water

Question 3

Explain why cystic fibrosis affects the rate of oxygen uptake in the lungs.

Answer 3

thick mucus, accumulation of mucus which can’t be moved by cilia, restricting air flow through bronchioles, increases diffuse distance in the alveoli