ASIM K8 Lab: Estimating # of Stomata in a

Lettuce Leaf

By: Lisa M. Clark

TCHS

Stomata• Structure

• Tiny pores located on bottom of leaf

• Oval shaped• Look a little bit like cat

eyes!• Two kidney-shaped

cells (guard cells) are found on each side of the stomata.

• Chloroplasts are also found in the guard cells.

• Function• Release extra water

from the leaf (called transpiration!)• Take in carbon dioxide • Release oxygen• Guard cells swell &

shrink to control the opening & closing of stomata

• Chloroplasts within guard cells carry out photosynthesis.

Click to the next slide to view a video that explains and shows

the function of stomata.

http://www.pnas.org/content/101/4/918/F1.large.jpg

a) 100X Total magnification

A magnified section of the leaf you see in figure b. Notice there are about 18 stomata.

b) 40X Total magnification

The underside of a leaf (not enough magnification to

see the stomata).

This picture also shows the lettuce leaf’s lower epidermis (~400X)

•The labeled parts are what you will identify in lab.

http://www.lima.ohio-state.edu/biology/images/stoma.jpg

Lower Leaf Epidermis (~1000X)

• This picture shows a plant leaf’s lower epidermis under the microscope.

• Look carefully at the labeled parts.

• These are the parts that you will label during lab.

www.tutorvista.com/.../protective-tissues.php

Labeled diagram of stomata & surrounding guard cells

http://image.tutorvista.com/content/plant-water-relations/stomatal-movement--dicot-plants.jpeg