Work-1: Observation of a plant cell (onion cell) under a microscope; Essentials: Onion, blade, slide, cover slip, watch glass, paint brush, glycerin and a microscope. Procedure: Peel the dry scale leaves of an onion. Now, take a wide, flesh scale leaf. After removing a small outer layer from the surface of the scale with the help of a blade, put it in water in a watch glass. Now, with a small paintbrush, place the scale piece on a clean glass slide after taking it from the water of watch glass. Leave a drop of glycerin on the specimen object to observe and slowly place the cover slip on it. Observation: Observe it under the objective with the lowest power. You will be able to see rectangular and thin walled cells. Now, observe them with an objective with higher power. In every cell, you will find thin, granular protoplasm, vacuole and a sided nucleus. Work-2: Observation of an animal cell (Amoeba) under a microscope. Essentials: Microscope, slide, cover slip, dropper, petriplate, pipette, glass rod, small bowl of glass and water.Procedure: At the beginning of the experiment, collect some rotten leaves with the branches of the plant from the bottom of a ditch or a pond. Cut them into smaller pieces and put the pieces in the water of the glass bowl and stir it steadily with a glass rod. After stirring the water for a while, set the bowl at rest in a place. When the things will be settled on the bottom of the bowl, draw some of the precipitation with a pipette and put it on a petriplate. Now, take a drop of the contents in the petridish on a glass slide with a dropper and after placing cover slip on it, set it to observe under a microscope. Observation: After searching for a while by moving the slide on two horizontal axes, you will find some transparent, jel-like small organisms. These are amoebas. Many pseudo pods and vacuoles will be found in it and there will be a plasma lemma surrounding the cell. There will be no plastids like a plant cell. Has there any difference been found between a plant and an animal cell? Draw and label what you have seen.
Posted on: Mon, 10 Jun 2013 01:05:42 +0000