Cells Biological

1414 wd

Experiment title: Preparation of Biological Materials for Microscopic Examination

Objectives:

1. To learn how to use a microscope. 2. To study the cell structure of starch grains, onion cells and cheek cells. 3. To differentiate the difference between starch grains, onion cells and cheek cells.

Introduction:

Microscope is an optical instrument use to magnify micro objects that hardly or impossible to be observed by naked eyes, so that the objects can be studied. Compound light microscope is one of the microscopes that is often used. It has a lens or a combination of lenses which magnifies objects, and a variety of knobs to adjust the stage. One of the lens system enlarge the image of the object and the second magnifies the image formed by the first. It uses light reflected from or passed through the sample being observed to form a magnified image of the object, refracting the light with an arrangement of lenses and mirrors similar to those found in telescopes (Houghton Mifflin Company 2003). On the other hand, the adjustment of knobs enables exact focus by moving object slightly while