gracticle

Question 1

Stomata are found mainly on the underside of leaves of dicotyledonous plants.

A student painted a layer of nail varnish on the lower epidermis of a leaf.

She peeled off the dry layer of nail varnish and placed it on a microscope slide. The student was able to see the impressions of the stomata on the varnish using an optical microscope.

She then determined the mean diameter of the stomata.

(a) Describe how the student could use an eyepiece graticule to determine the mean diameter of stomata.

Answer 1

Measure (each stoma) using eyepiece graticule;

2. Calibrate eyepiece graticule against stage micrometer / ruler / graph paper;
3. Take a number of measurements (to calculate a mean);
4. Accept micrometer slide