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Practical: Study of Nostoc

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 Practical: Study of Nostoc Nostoc is a filamentous, photosynthetic cyanobacterium. It commonly occurs in freshwater, moist soil, wet rocks and other damp habitats. Colonies are usually gelatinous because numerous filaments remain embedded in a mucilaginous matrix. Materials Required Fresh or preserved Nostoc material, clean glass slide, cover slip, dropper, dissecting needle, water, blotting paper and compound microscope. Procedure Take a small quantity of Nostoc colony with the help of a dissecting needle and place it on a clean glass slide. Add one or two drops of water and gently tease the material so that the filaments become separated. Place a cover slip carefully over the material without trapping air bubbles. Remove excess water with blotting paper. First observe the preparation under low power and then under high power of the compound microscope. Observations The plant body of Nostoc is thalloid and usually forms a soft, jelly-like colony. A colony contains numerous ...
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Morphology of Psilotum

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Morphology of Psilotum 1. Introduction to Psilotum Psilotum belongs to the family Psilotaceae and order Ophioglossales of the vascular plant division (Pteridophyta). It is the only genus of the family Psilotaceae. In total, there are about 18 species of Psilotum belonging to the genus, out of which 2 occur in India viz., P. nudum and P. triquetrum. The plants of this genus are popularly known as whisk ferns, as they resemble the whiskers of some animals. Psilotum species are unique plants with small, leaf-like stems that absorb water and nutrients. They are classified as vascular plants with xylem and phloem, but lack most features common to vascular plants. Unlike other vascular plants, species of this genus do not have true leaves, roots or flowers. Instead of conventional green leaves, they have flattened photosynthetic branches that perform photosynthesis and help in the growth of new branches. Flora of Psilotum exist in two different forms. Some are terrestrial, found in rainfore...
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