Leaves Under the Microscope

LEAVES UNDER THE MICROSCOPE

Name: ______Hr: ____

Objective

1. You should be able to use a microscope to focus on a prepared impression of a leaf.

2. You should be able to identify important microscopic leaf structures by comparing what you observe under the microscope with images and descriptions in your textbook.

Procedure

1. Acquire a leaf from a pin oak tree as directed by your teacher.

2. Apply a thin dime sized field of clear fingernail polish between the mid-vein and the edge of the leaf, towards the base of the leaf on its underside. Let the fingernail polish dry over the next five minutes, or until dry to the touch.

3. While waiting acquire a small piece of clear binding tape. When the fingernail polish has dried, removing the backing from the tape, place the tape over the fingernail polish, rub it down with a fingernail, and then carefully remove the tape with attached fingernail polish. You should see a distinct silvery area on the tape.

4. Place the tape on a clean glass slide, acquire a microscope, and follow the directions in the handout titled “Tips on Focusing a Microscope” to focus on the impression of the leaf at high power.

5. Once you have a clear image of the leaf use your book to find out what is in the image and complete question 1 below.

Question

1. Draw a sketch of the leaf as viewed under the microscope. Label some important features and in the adjacent area describe the function of any structure that is important to the process of photosynthesis. 2. How is having these circular structures beneficial for a plant?

3. How is having these circular structures harmful or a liability to the plant?

4. Use the internet to determine how the guard cells that regulate stomatal opening and closing. Describe what you find below.