Stomata counts

What are the 4 steps to make a replica of the epidermis

• Place the leaf facing downwards so the lower epidermis is facing upwards

• Apply a thin layer of colourless nail varnish between the veins

• Wait for it to dry

• Stick some sellotape over the nail varnish then peel away maintaining tension

• Stick the sellotape onto the microscope slide

What are the 3 steps for counting the stomata

• Using a microscope focus using the x10 objective lens then refocus with the x40 objective

• Count the number of stomata in the field of view

• Repeat for 3 fields of view to calculate a mean

What’s the calculation for the size of the field of view

Height / Magnification x Width / Magnification

How do you work out the number of stomata per mm²

Number of stomata /size of the field of view

What 4 environmental factors should be controlled

• Carbon dioxide concentration

• Water availability

• Wind speed

• Humidity