Science Tech

  

 Usefulness of plants and human affairs (utility) Food Plants are the main source of food for humans. Plants, unlike humans and animals, manufacture their own food. They do so by the process known as photosynthesis in their green leaves by use of sunlight.  They can convert and store the light energy in the … Read more

The peripheral nervous system (PNS) consists of all neurons that exist outside the brain and spinal cord. This includes long nerve fibers containing bundles of axons as well as ganglia made of neural cell bodies. The peripheral nervous system connects the central nervous system (CNS) made of the brain and spinal cord to various parts … Read more

 Impact of Solid Waste; Recycling and Reuse HEALTH AND ENVIRONMENTAL EFFECTS An effective solid waste management system is necessary to avoid public health disasters, spread of disease by insects and vectors and adverse effect on water and air. Solid waste workers are the most exposed to the risks of parasitic infections and accidents, … Read more

 Acid An acid is a substance which forms H+ ions as the only positive ion in aqueous solution. Examples:- Hydrochloric acid dissolved in water forms H+ and Cl– ions   HCl —> H+ + Cl–   Sulphuric acid dissolved in water forms H+ and SO42- ions   H2SO4 —>2H+ + SO42-   Nitric acid forms H+ and NO3– ions when dissolved in water … Read more

 Electric discharge in gases Electrical discharge through gases is studied by using a specially designed glass tube commonly called as a discharge tube. It consists of a cylindrical glass tube having a side tube, and two metallic electrodes one at each end. These electrodes can be connected to the respective terminals of a … Read more

Preparation and properties of commonly used dyes Dye, substance used to impart colour to textiles, paper, leather, and other materials such that the colouring is not readily altered by washing, heat, light, or other factors to which the material is likely to be exposed. Dyes differ from pigments, which are finely ground solids dispersed in … Read more

 Carbohydrates (glucose, sucrose and cellulose) Carbohydrates (also called saccharides) are molecular compounds made from just three elements: carbon, hydrogen and oxygen. Monosaccharides (e.g. glucose) and disaccharides (e.g. sucrose) are relatively small molecules. They are often called sugars. Other carbohydrate molecules are very large (polysaccharides such as starch and cellulose). Carbohydrates are: a source of energy … Read more

  

 Chromosomes Chromosome, the microscopic threadlike part of the cell that carries hereditary information in the form of genes. A defining feature of any chromosome is its compactness. For instance, the 46 chromosomes found in human cells have a combined length of 200 nm (1 nm = 10− 9 metre); if the chromosomes were … Read more