9. Microscopes

The resolving power of a microscope is described as the ability of the microscope to:

If you can only increase one of the following, which would you increase to observe more details of the microscopic specimen?

Fill in the following blanks.

a. 1 μm = ______ m

b. 1= _______ 10⁻⁹ m

c. 1 μm = ______ nm

Calculate the total magnification of the nucleus of a cell being observed through a compound light microscope with a 10x ocular lens and an oil immersion lens.

The maximum magnification of a compound microscope is (a) ________; that of an electron microscope, (b) ________. The maximum resolution of a compound microscope is (c) ________; that of an electron microscope, (d) ________. One advantage of a scanning electron microscope over a transmission electron microscope is (e) ________.

Immersion oil improves resolution by:

a. limiting light refraction.

b. magnifying the specimen.

c. improving specimen contrast.

d. making light waves shorter.

e. making light waves faster.

Assume you are asked to view and draw all samples at a final magnification of 1000x. If the ocular lens is 10x, what objective lens should be in place as you draft your drawings?

A nanometer is _______ than a micrometer.

a. 10 times larger

b. 10 times smaller

c. 1000 times larger

d. 1000 times smaller

Resolution is best described as the ____________.

a. ability to view something that is small

b. ability to magnify a specimen

c. ability to distinguish between two adjacent objects

d. difference between two waves of electromagnetic radiation

Curved glass lenses _______light.

a. refract

b. bend

c. magnify

d. both a and b

Which of the following factors is important in making an image appear larger?

a. thickness of the lens

b. curvature of the lens

c. speed of the light passing through the lens

d. all of the above

Immersion oil ________(increases/decreases) the numerical aperture, which ________(increases/decreases) resolution because _______(more/fewer) light rays are involved.

________ refers to differences in intensity between two objects.

Critique the following definition of magnification given by a student on a microbiology test: “Magnification makes things bigger.”