Microscopy

Question 1

What stain is used on onion skin slides?

Answer 1

Iodine solution

Question 2

What does a microscope coarse adjustment knob do?

Answer 2

Moves the objective lens towards or away from the slide more rapidly and in larger increments.

Question 3

What is the order of steps when focusing under the microscope?

Answer 3

1. Select the lowest power objective lens.
2. Use the coarse adjustment knob to lower the lens closer to the slide.
3. Look through the eyepiece and use the coarse adjustment knob to bring cells into focus.
4. Refine focus with the fine adjustment knob

Question 4

How do you calculate the total magnification when drawing observed cells?

Answer 4

total magnification = lens magnification x objective lens magnification

Question 5

What is the purpose of methylene blue when making cell cheek slides?

Answer 5

It selectively binds to DNA, resulting in a darker blue stain of cell nuclei. This makes it easier to identify cells under the microscope.

Question 6

What does the microscope fine adjustment knob do?

Answer 6

Make refined and subtle changes to the focus for an optimised, clear image.

Question 7

What are the guidelines for good scientific drawings?

Answer 7

1. Label with sample name and magnification
2. Use pencil
3. Neat outlines, no sketchy lines
4. No shading or colour
5. Clear labels with ruler lines
6. Clean, no smudges