Question

Image formation in electron microscope is based on ___________________________

(a) column length

(b) electron number

(c) differential scattering

(d) specimen size

This question was posed to me in an online interview.

The origin of the question is Techniques topic in section Techniques in Cell Biology of Cell Biology

Answer 1

In an electron microscope, image formation primarily relies on differential scattering of electrons. When a beam of electrons passes through or interacts with a specimen, different parts of the specimen scatter the electrons to varying degrees based on the density and atomic composition of the material. This scattering creates contrast, allowing for the formation of a detailed image.

Let's analyze the options:

• (a) Column length: While the length of the electron microscope column affects magnification, it does not directly impact image formation.

• (b) Electron number: The number of electrons in the beam can influence image brightness but is not the basis for image formation.

• (c) Differential scattering: This is correct. The variation in scattering patterns creates contrast and is the primary basis for image formation in electron microscopy.

• (d) Specimen size: While the size of the specimen is relevant for sample preparation, it does not directly determine the formation of the image.

Correct Answer: (c) Differential scattering