In addition to staining a specimen to increase the contrast between the specimen and its surroundings, you can use the condenser, iris diaphragm, and the light source to adjust the light to produce better contrast of unstained specimens. (This may not be stated specifically or be correlated in this way, in the lab manual, but students should be able to deduct the answer from information provided and experience with the microscopes) a. True
b. False

Light microscope:

use a beam of light to produce magnified imagescan be used to examine living cells and tissues

Scanning electron microscope:

use a beam of electrons to produce magnified imagescan be used to examine DNAcan be used to examine cells

Transmission electron microscope:

use a beam of electrons to produce magnified imagescan be used to examine DNAcan be used to examine cells

Explanation:

Light microscope: is a commonly used microscope also known as compound microscope. Magnifies images from 40X upto 1000X. It uses ray of visible light to produce a magnified image. The light microscope can be used to view specimen of both living and dead cells or tissues. However, it doesn't give a detailed view of a specimen like electron microscope.

Scanning electron microscope: It uses electron beam as an illuminating source. It has a much higher resolving power than light microscope because it uses electrons instead of light. It magnifies object upto 500000 times the actual size. Internal structures can also be viewed. However, only dead specimen can be used because the beam of electrons can kill the cells. They are of two types:

Scanning electron microscope(SEM): an electron beam passes over the specimen's surface and displaces electrons which are then focused on  a screen to form an image. Images appear in 3-DTransmission electron microscope: electromagnets magnify the image by passing beam of electrons through a thin specimen. Images appear in 2-D