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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 ...

MCQ BIOLOGY2023-01

  1. Which cells have routinely used to understand structure of plasma membrane? a) Neurons                    b) Mylein cells c) RBC                         d) Stem cells   2. Cholesterol contributes to which of the following properties of biological membranes of animals? a) Membrane rigidity   b) Membrane fluidity c) Membrane permeability d) Membrane osmolarity   3. Cell membrane is always a) Static condition b) Dynamic condition c) Partially static condition      d) Fragmented structure   4. Which of the following statements concerning biological membrane is correct? a) Aquaporins are hollow pore b) Lipid composition of two layers of the membrane equilibrate c) The membrane is most fluid at the surface d) Fli...

MONKEY

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