Biology 9700 · AS & A Level · The gas exchange system
The gas exchange system — practice question
Fig. 1.1 shows a light micrograph of a section cut through part of the gas exchange system. A, B and C represent three distinct tissue types.
(a)[3]
The cell types in tissue $A$ carry out different roles. Describe how these cell types act together to keep the gas exchange system healthy.
(b)[1]
Suggest why the cells in tissue $B$ contain many mitochondria.
(c)[1]
Name the parts of the gas exchange system in which tissue $C$ is found.
Worked solution & mark scheme
This 5-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Identifies goblet cells and ciliated epithelial cells” …