9. Microscopes

Electron microscopes differ from light microscopes in that:

There are two major types of electron microscopes, Transmission Electron Microscopes (TEM) & Scanning Electron Microscopes (SEM). What are the major differences between these types of electron microscopes?

Which of the following is true?

a. SEM is higher resolution than TEM.

b. Most viruses can be seen using a light microscope.

c. Simple staining involves an acidic and a basic dye in combination.

d. Samples can be stained or unstained for light microscopy.

e. These are all false statements.

Indicate which form of electron microscopy is being described: SEM, TEM, or both.

a. Images the external surface of a specimen

b. Sample must be thinly sliced prior to viewing

c. Provides details about internal structures of the sample

d. Can be used to image viruses

e. Provides black-and-white images

f. Specimen is dead

Explain how the principle, “electrons travel as waves,” applies to microscopy.

Why can electron microscopes magnify only dead organisms?

An atomic force microscope can magnify a living cell, whereas electron microscopes and scanning tunneling microscopes cannot. What requirement of scanning tunneling microscopes precludes the imaging of living specimens?