A compound microscope is used for viewing small objects as it magnifies the image and makes it easy to observe them.
The diaphragm is a part of the compound microscope which is used for adjusting the amount of light so that one can view the specimen in a suitable manner.
The light source is located just under the stage where the slide is placed and the rotation of the diaphragm allows to adjust the intensity of the light illuminating the specimen.
There are three widely recognized domains: Archaea, Bacteria, and Eukarya. Viruses lack many traits of living things so the majority of scientists do not classify them as living organisms.
