Study Of Tissues And Diversity In Shapes And Sizes Of Plant And Animal Cells

Purpose of the Experiment

This experiment focuses on examining the various tissues and the diversity in shapes and sizes of plant and animal cells such as guard cells, palisade cells, parenchyma, sclerenchyma, collenchyma, phloem, xylem, squamous epithelium, mammalian blood smear and muscle fibres. This is achieved through the preparation of permanent/temporary slides.

Concept

What Does Tissue Mean?

A tissue is essentially a group of cells that perform a similar function and are similar in shape and size. Tissues can be categorized as follows:

• Simple tissue – These contain only one type of cell. They can be further classified into parenchyma, collenchyma and sclerenchyma.
• Complex tissue – These contain more than one type of cell and can be classified as meristematic tissue and permanent tissue.

Cells of different types of tissues vary in their size, structure, shape, wall composition and function.

Related Link: Plant Tissue System

Materials Needed

A. Permanent Slides of:

• T.S of Nerium Leaf, T.S of Lotus leaf, T.S of Lotus stem/petiole
• V.S of root apex and shoot apex
• T.S of Mentha/Cucurbita stem
• Macerated material of Tridax, Vitis/Bougainvillea

B. Requirements for Maceration Technique

• Small branches of locally available plants
• Safranin
• Glycerine
• 100ml Beaker or Boiling test tube
• Cotton blue
• Slides
• Glass rod
• Needles
• Tripod stand
• Burner
• Wire gauge
• Microscope
• Sharp-edged Knife
• Thread
• Cheese or muslin cloth

Maceration Fluid

• Chromic acid should be dissolved with an equal quantity of 10% nitric acid
• Preparation of chromic acid is done by adding 100ml of concentrated H₂SO₄ gradually in 10ml of water
• Now add K₂Cr₂O₇ (potassium dichromate) – 50gm
• The stock solution is ready. 10ml of this solution is diluted up to 100ml for the preparation of the working solution of the maceration liquid.