01. Observing cells and estimating size

Learning objectives: ability to draw biological structure and identify components of cells

1. Prepare slides of thin slices of cork and look at them through the microscope.

What excited Hooke so much?

2. Prepare slides of any other material and view this through the microscope. For each slide make a simple biological drawing of what you see and write a description, using labels if possible.

Examples include:

• live Elodea or pondweed leaf with a drop of water and cover with a cover slip.

• onion epidermis- use the inner curved papery thin epidermis, stain with a drop of iodine solution and cover with a cover slip.

Experiment: Observing cells and estimating their size o potato- try to slice thin enough sections with scalpels, stain with a drop of iodine solution and cover with a cover slip.

1. tulip leaf epidermis- tear the leaves so that you separate the thin transparent epidermis from the mesophyll tissue. Lay the epidermis on a slide with a drop of water and cover with a cover slip.

2. prepared slides of

   • blood smears

   • stem and root tissues

   • muscle cells

3. Record your observations in the form of annotated biological diagrams. Include notes about

• relative size / or magnification

• cell shapes

• colours

• items inside the cell ( Elodea, potato)

4. Estimate cell size