CAIE A Level Biology 9700 · Control and coordination
A student observes a Venus fly trap (Dionaea muscipula) in a laboratory. A small insect lands on one of the modified leaves and brushes against two of the trigger hairs within 20 seconds. The trap then snaps shut within 0.1 seconds. Describe the sequence of events that leads to this rapid closure.
4 marks, so the mark scheme is looking for about 4 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.