Science Tech

 Biopesticides Plants, growing in the wild or in cultivation, face numerous threats from insects, bacteria, viruses, and fungi, as well as from other plants. Biopesticides are inert substances or living organisms that can help protect plants from such threats. Chemical pesticides can offer similar protection but, by contrast, are neither alive nor made … 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

 Electric current Ohm’s law and Resistance   Electrical current is the flow of charged particles. The flow of charges will be constant in current electricity. Electric current flows from higher electric potential to lower electric potential. For the current to flow, it requires a circuit which is closed loop of a conducting material. … Read more

 Vaccines A vaccine is a biological preparation that improves immunity to a particular disease. A vaccine typically contains an agent that resembles a disease-causing microorganism, and is often made from weakened or killed forms of the microbe, its toxins or one of its surface proteins. The agent stimulates the body’s immune system to … Read more

 Diseases related to kidney Abderhalden-Kaufmann-Lignac syndrome Autosomal recessive syndrome of disturbance of amino acid transport characterized by deposition of cystine crystals in numerous tissues of the body, particularly evident in the conjunctiva and cornea. Children in whom cystinosis is found are subnormal in development, with dwarfing, rickets, and osteoporosis. Renal tubular disease, aminoaciduria, … Read more

 Microscope Microscope, instrument that produces enlarged images of small objects, allowing the observer an exceedingly close view of minute structures at a scale convenient for examination and analysis. Although optical microscopes are the subject of this article, an image may also be enlarged by many other wave forms, including acoustic, X-ray, or electron … Read more

 Respiratory System Introduction Red blood cells are like trucks that transport cargo on a highway system. Their cargo is oxygen, and the highways are blood vessels. Where do red blood cells pick up their cargo of oxygen? The answer is the lungs. The lungs are organs of the respiratory system. The respiratory system … Read more

 PN Junction Diode A PN-junction diode is formed when a p-type semiconductor is fused to an n-type semiconductor creating a potential barrier voltage across the diode junction The effect described in the previous tutorial is achieved without any external voltage being applied to the actual PN junction resulting in the junction being in … Read more

 Topological & Non-Topological Conservation    Conservation – shape and structure of networks of interacting organisms in ecological systems In-Situ Conservation    Protect whole ecosystem at all levels to protect threatened species (save entire forest to save tiger)  Hot Spots – High endemism & high species richness (in India – Western Ghats (Agasthyamalai hills, … Read more

 Ray optics Nature of light Light is a transverse, electromagnetic wave that can be seen by humans. The wave nature of light was first illustrated through experiments on diffraction and interference. Like all electromagnetic waves, light can travel through a vacuum. The transverse nature of light can be demonstrated through polarization. Light is … Read more