Practical Skill: Microscopy & Drawing Scientific Diagrams

Question 1

When using an optical microscope always start with the low ………. as this is easier for what and prevents what

Answer 1

power objective lens:
It is easier to find what you are looking for in the field of view

This helps to prevent damage to the lens or coverslip incase the stage has been raised too high

Question 2

A graticule must be used to take measurements of cells:
A graticule is a

Answer 2

a small disc that has an engraved scale. It can be placed into the eyepiece of a microscope to act as a ruler in the field of view

Question 3

as a graticule has no fixed units it must be done and how is this done

Answer 3

has no fixed units it must be calibrated for the objective lens that is in use. This is done by using a scale engraved on a microscope slide (a stage micrometer)

Question 4

By using the two scales together the number of micrometers

Answer 4

each graticule unit is worth can be worked out

After this is known the graticule can be used as a ruler in the field of view