L.16 EPIDERMIS CELLS

OBJECTIVES:

- Identify the shape of epidermis cells.
- Identify and explore the parts of a stoma.
- Measure dimensions of the entire cell and the stoma.

MATERIALS:

- 1 Slide

- 1 Cover slip
- Distilled water
- 10% Salt water
- Scissors
- Needle

PROCEDURE:

Plant cells observation:
1. Cut the stalk of the leek.
2. In the place of the cut, pull out the transparent part of the epidermis using forceps.
3. Using the brush, place the peel onto the slide containing a drop of tap water.
4. Take a cover slip and place it gently on the peel with the aid of a needle.
5. View it in the microscope.
6. Describe the change in the shape of the cells.
7. Draw a diagram with the parts of a stome: stoma,cell guards,epidermis cells.

Salt treatment:
1. Prepare a 10% of salt solution.
2. Put the salt with a dropper on the left part of the slide.
3. Place a piece of cellulose paper in the opposite part of the cover slip, and let the dissolution to go though your sample.

RESULTS AND CONCLUSIONS:

1. What is the major function of a cell membrane?
The basic function is to maintain the plasma membrane via the differential intracellular environment. The combination of active and passive transport makes the plasma membrane selective barrier that allows the cell to differentiate medium.
2. What is the major function of the cell wall?
Cell wall protects the cell contents and gives rigidity to the cellular structure.
3. How does salt affect the cells shape? And the stomes?
altering the sodium concentration gradient both outside and inside the cell ions.