1. Diagrams A, B and C show cells from different parts of the human body, all drawn to the same
scale.
A
B
С
Key
- Mitochondrion
Ribosome
(a)
Which cell, A, B or C, appears to be best adapted to increase diffusion into or
out of the cell?
Give one reason for your choice.

If you were given a map of the sensory cortex in the postcentral gyrus of the cerebrum, do you think the map would have more “space” devoted to the regions of the body that have the highest density of sensory receptors, or the regions of the body that have the lowest density of sensory receptors? explain.