CAIE A Level Biology 9700 · Cell membranes and transport
In an animal, a signalling molecule produced by an endocrine gland travels to its target cells. Describe the sequence of events that occurs from the secretion of the signalling molecule to the final response in the target cell. Use the fluid mosaic model of the cell surface membrane to explain how the signalling molecule interacts with the target cell.
5 marks, so the mark scheme is looking for about 5 separate creditworthy points. Making the same point twice in different words earns it once.
Describe means: Say what happens or what something is like, in order and with detail. You are not being asked why. If there is data, quote it: name the trend, then give figures with units at the points where it changes.
Written by Markquill to follow the Cambridge International syllabus. Markquill is independent and is not affiliated with or endorsed by Cambridge International.