HARD
AS and A Level
IMPORTANT
Earn 100

Describe in detail that can be seen in a TEM of a ciliated epithelial cell that cannot be seen under high power with a light microscope.

Important Questions on Gas Exchange

HARD
AS and A Level
IMPORTANT
Describe the pathway taken by a molecule of oxygen as it passes from the atmosphere to the lungs.
HARD
AS and A Level
IMPORTANT
Explain how alveoli are adapted for gas exchange.
HARD
AS and A Level
IMPORTANT
How many times does an oxygen molecule cross a cell surface membrane as it moves from the air into a red blood cell, Explain your answer.
HARD
AS and A Level
IMPORTANT
The electron microscope was needed to confirm that each alveolus is completely surrounnded by epithelial cells. Explain why?
HARD
AS and A Level
IMPORTANT

The following structures are found in the walls of the gas exchange system.

1 Cilia

2 Elastic fibres

3 Smooth muscle cells

4 Goblet cells

5 Squamous epithelial cells.

Which would be found in the lining of an alveolus.