optimal level of activity

The molecules of various chemical substances in a specific proportion become organised into protoplasm - the physical basis of life. The protoplasm gets organised into cells, which represents the structural and functional unit of life. A living organism may have a single cell (unicellular) or many..

Fluids Pressure Upthrust and Flotation..

Change in the composition of air due to several human activities has brought about green house effect. Green house effect has brought about following phenomenal changes. The severity of these changes will aggravate further in the next 10-20 years. By 2040, CO 2 level in a..

Sewage treated in primary treatment is brought in contact with oxygen and aerobic micro-organisms. They break down the organic matter into harmless materials as CO 2 and H 2 O. Further, chlorination is done to reduce the bacteria. It may be further treated to tertiary level zero measure..

All living beings require a constant supply of energy for the various functions they perform. The energy is obtained from the sun. This energy is introduced into the biosphere by green plants by a process known as photosynthesis. Plants are able to trap this light energy and by the process of phot..

Transport facility created for the convenience of human beings is a great source of air pollution as all the transport vehicles burn some kind of fuels and emit dangerous gases. The extent of gases produced by an individual vehicle may be less. But, when large number of vehicles are used - the air ..

The Greenhouse effect is the rise in temperature that the Earth experiences because certain gases in the atmosphere (referred to as greenhouse gases), trap energy from the Sun. Without these gases heat would escape back into space and living on Earth would be inhospitable with average temperature b..

The following experiment shows this property of adsorption (Fig.10.8). Place a jar of dry ammonia over mercury. Adjust the levels of mercury inside and outside the bell jar till they are equal. Carefully, push in a large piece of charcoal, preferably, activated charcoal. You wi..

Pyramid of Energy - "Pyramid of energy is a graphic representation of the amount of energy trapped per unit time and area in different trophic level of a food chain with producers forming the base and the top carnivores at the tip". Pyramid of Energy in a Food Cha..

, (+) - thyroxine, has none of this effect but is used to lower the cholesterol levels. In foods, the chirality of compounds determines the nutritional value, sensory properties or biological activity. Enantiomers of a chemical may have very different flavors. Detection of an un..