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The seed After fertilization, ovaries develop into fruits and ovules into seeds. Seed contain a baby plant called an embryo and reserve food in fleshy parts called cotyledons. An embryo has two important parts plumule and redicle. Seeds have small scar on its surface called hilum. This is the point where seeds are attached to the fruit wall( . . .
The fruit The fruit is the ripened ovary. Tomato, pumpkin and pea all are fruits not just vegetables. A vegetable can be any part of plant root, stem, leaf or fruit which can be cooked and eaten. Apple and pear are different kinds of fruits, in these , the base of flower becomes the main fleshy part of fruit, which we eat while the ovary rem . . .
There are so many chemical compounds which are widely used in chemistry and play an important role in our domestic life, Industries and in analytical chemiatry. Following is the list of such compounds with their chemical formula, chemical name & common name. . . .
Thrombocytes (Platelets) Structure • Minute, oval or round, non - nucleated Count • 200,000 to 400,000 per mm3 Production & death • Budded off from some giant cells (megakaryotes) in red bone marrow. • Life span is 3 to 5 days • Destroyed mainly in spleen Function • Helps in blood clott . . .
Artery Carries oxygenated blood away from the heart towards organs. Narrow lumen. Blood flow with jerk due to ventricular systole. Progressively branched & decreasing in size. Smallest artery breaks in to arterioles. Thick, muscular & elastic walls. Have no valve in inner linings. Constricts & dilate to control blood flow . . .
Light & dark adaptation Dark adaptation • When a person come in a dark room from a bright lighted area it is difficult to see objects for some time after that the vision is improved & the person can see objects clearly. • This is done by (i) The regeneration of visual purple (rhodopsin), the pigment of rods, which was earlier broke . . .
Different metals show different reactivity towards different chemical compounds. Following chart shows the chemical properties of metals. . . .
Blood Clotting - Coagulation of blood at wound to prevent excess loss of blood. Clotting occurs in a series of steps as follows - 1. At the site of wound, platelets release an enzyme thrombokinase or thromboplastin (also called Factor 'X' or Stuart factor) 2. Thrombokinase along with calcium ion present in blood plasma, conver . . .
ANTIBIOTICS An antibiotic is a chemical substance produced by a living organism which can stop the growth of some disease producing bacteria and fungi. Antibiotics are widely used in the treatment of numerous infections. Ex. Streptomycin, chloromycetin, tetracycline and penicillin. Penicillin is the first produced antibiotic. It is the . . .