Multiple choice

Bacteria are observed under a microscope without staining when they are opaque or nearly invisible to the naked eye, why?

  1. They are a watery type. That is why they are opaque without staining under microscope.

  2. They are too small to see under microscope.

  3. Bacteria have nearly the same refractive index as water.

  4. Bacteria have more refractive index than water.

  5. Bacteria have less refractive index than water.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Bacteria have nearly the same refractive index as water, therefore, when they are observed under a microscope they are opaque or nearly invisible to the naked eye. So, different types of staining methods are used to make the cells and their internal structures more visible under the light microscope.

Keep practicing — related questions