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Showing posts with the label BIOLOGICAL ARTICLE

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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Insecticides: Types

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  Classification of Insecticide: Based on mode of entry A) Stomach poisons : Those insecticides that reach through their food into the target insect's body are considered stomach poisons. These insecticides are sprayed on the plants or dusted, and when the insects eat parts of these plants including leaves, tender stems, seeds, etc., they enter the stomach and kill them. Stomach insecticides are very effective against insect pests having biting and chewing types of mouth parts. Example-  Malathion.   B) Contact poisons:  Such insecticides that enter the insect's body through their cuticles or spiracles. The pest may absorb the poison when walking on the treated ground, flying through a mist or fine droplets, or when the insecticides are directly hit during spraying or dusting. Example- Fenvalerate.   C) Fumigants:  The insecticides that penetrate the insect's body through the spiracles and tracheae in a gaseous state. In closed spaces, they are most effecti...
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Organism and Environment Interactions into The Basic Theory of Community and Evolutionary Ecology

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Organism and Environment Interactions into The Basic  Theory of                                                  Community and Evolutionary Ecology Abstract: Understanding the interactions of an organism and its environment is essential for us to integrate ultimate and proximate causation on a global scale. Organism–environment interaction includes all organisms including animals, plants, and non-eukaryotes, etc. because all of them are responsive to environmental change including those that are human-induced. Implications for climate change in which weather extremes will become more common again suggest a mechanistic approach will be important to understand how organisms may respond. Organism–environment interaction is a fundamental concept that may unify ultimate and proximate causation and point the way for future investigations striving to understand co...
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