CAIE A Level Biology 9700 · Cell structure
A student views a thin section of onion root tip using both a light microscope (LM) and a transmission electron microscope (TEM). The LM image shows cell outlines and nuclei, while the TEM image reveals the internal structure of mitochondria and endoplasmic reticulum.
Describe why the TEM can resolve these finer details that the LM cannot.
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.