Plant and Animal cell

 Study of plant cells (onion peel cells)                                                    Materials Required - Onion peel, Watch glass, Glass slide, Cover slip, Paint brush, Microscope, Water Method Cut an onion and obtain an inner fleshy tissue as shown in the diagram. Remove a peel from inner or outer surface of it and transfer it on to a watch glass containing water. Put a water drop on to a clean glass slide and transfer the specimen on to the slide using a paint brush. Cover it with a cover slip without trapping any air bubbles and observe it through the microscope.

 Study of animal cells (cheek cells)                           Materials Required - Sample of cheek cells, Glass slide, Cover slip, Microscope, Water Method Wash the mouth and scrape the inner side of the cheek using a yoghurt spoon. Obtain a clean glass slide and put a drop of water and transfer the specimen on to the slide. Cover the specimen using a cover slip without trapping any air bubbles and observe through the light microscope.

 3 Structure of cells  Let’s see the following videos to study the structure of animal cells and plant cells. To study the animal cells we will observe cheek cells and for the plant cells, let's take onion epidermal cells, as these cells are easily obtained.

 2 Concept of the cell   The cell is the smallest structural unit of the organization of the living body. The organisms composed of a single cell are called unicellular organisms and those of many cells are called multicellular organisms. Cells perform different functions in the body. For example - The transportation of oxygen is done by red blood cells.   Transmission of impulses is done by neurons.  Accordingly, the smallest bio unit that is adapted to perform a particular function is the cell. So it is clear that the structural and functional unit of life is the cell. The cells differ from one another from their shape, size and function. Except few occasions, mostly cells are not visible to the naked eye. Therefore they have to be observed using the light microscope.

 1.Basic unit of life  In 1665, Robert Hooke observed a section of a cork using a microscope prepared by him. He discovered a structure like chambers in a beehive and he named them as cells. Schleiden, Schwann and Radolf Virchow introduced the cell theory, based on the facts revealed by observing different live tissues through the microscope. The contents of the cell theory are as follows.  The structural and functional unit of life is the cell.  All organisms are made up of one or more cells.  New cells are formed from pre-existing cells.