Topic 2a- Cell Division- Investigating Mitosis

Question 1

How do you stain root cells on slides?

Answer 1

Rinse the root tip in water on a watch glass and then put the root on the microscope slide. Cut off the root tip for staining. Discard other root material. Add the stain and macerate the root tip with a mounted needle.

Question 2

How to use an optical microscope?

Answer 2

Clip the slide on the stage, select the lowest powered objective lens, use coarse adjustment knob, look down the eyepiece, adjust the focus with fine adjustment knob, until clear image.

Question 3

How do you use graticules?

Answer 3

Select the desired magnification and objective. Place the stage micrometer on the stage. Line up the scales of the micrometer and the eyepiece graticule. Count the number of divisions on the eyepiece graticule equivalent to each division on the stage micrometer.

Question 4

How do you calculate mitotic index?

Answer 4

Number of cells with visible chromosomes divided by total number of cells observed.