Laboratory Review 2

Explain the designation "compound light" Microscope

a. Compound: refers to the use of two sets of lenses- ocular & objective B. Light: uses light rays that are magnified and focuses by lenses

What function is performed by the diaphragm of a microscope?

It controls the amount of illumination used to view the object

What objective should be in place when the microscope is store away?

Scanning

What type of light microscope should be used to view a 50nm virus? Why?

An electron microscope, because a compound light microscope's resolution is up to about 200 nm, while a transmission electron microscope's resolution is about 0.1 nm.

How much larger than normal does an object appear with a low-power objective lense?

10x (ocular) times 10x (low-power objective) = 100x

What type of microscope, aside from the compound light microscope, might you use to observe the organisms found in pond water?

A stereomicroscope (dissecting light)

Why is locating an object more difficult if you start with the higher power objective than with the low-power objective?

Because it has a smaller diameter of field/ field of view

If threads are layered from top to bottom (blue, orange, green, yellow) which thread will come into focus first if you are using microscopy properly?

Blue

Why is it helpful for a microscope to be parfocal?

Little, if any, adjustment is needed when switching from low to high power. It allows for the object to stay in focus when switching magnification.

If the total magnification of a slide is 400x and the ocular lenses are 10x, what is the magnifying power of the objective being used?

Total magnification= ocular x objective. So 400x/10x = 40x