biological magnification ddt

Certain harmful substances, usually ones not found in nature but introduced by man, may get into plants and/or animals. These poisonous substances may not be broken down in the body or excreted easily, efficiently and quickly. Instead, they accumulate in the tissues, and as the living organism eats..

The study of food chains helps in understanding food relationship and interdependence among various organisms in an ecosystem. The mechanism of transfer of food, energy and nutrients through various components of nature can also be studied The effect of the use of pesticides on the ecosyste..

Certain harmful substances, usually ones not found in nature but introduced by man, may get into plants and/or animals. These poisonous substances may not be broken down in the body or excreted easily, efficiently and quickly. Instead, they accumulate in the tissues, and as the living organis..

Where many pesticides are extensively used to kill insects like mosquitoes. Apart from killing mosquitoes, these chemicals cause large pollution to drinking water, soil as well as many food stuff. For e.g., Spraying DDT, BHC to control mosquito based human diseases is extensively taken up..

Large scale death of aquatic and terrestrial animals Reduced reproduction rate Increased incidence of diseases Imbalances created in secondary food chains Accumulation of bioaccumulative and non-biodegradable pollutants in animal bodies. Some organochlorine pesticides (like DD..

Significance of Food Chains - Food chain studies help, a) understanding the feeding relationships and the interaction between organisms in any ecosystem. b) comprehend the energy flow mechanism and matter circulation in ecosystems. c) understand the movement of toxic substances and the problem of '..

Death of animals, birds Reasons - Ammonia released by carcasses of animals, birds. Water collection from forest areas - For e.g., Nitrates and ammonia compounds from rich forest soils Natural mineral deposits - For e.g., Deposits of bauxites The secondary source of water pollution can be a..

It is a sophisticated form of microscope, which can provide a higher magnification of the object (up to 1,00,000 times or more). The electron microscope employs an electron beam emanating from a cathode, instead of light as in the compound microscope. It uses coils instead of lenses. fig...

Pollution is defined as an 'undesirable change in the physical, chemical or biological characteristics of air, water and land brought about by man's activities that may harmfully affect living organisms and other resources'. Man, in his quest for a better life and more conveniences, is ge..

where the pollutant entering the water course affects the quality of water at a far off place, where no pollutant would have been added. For e.g., DDT found in sea water The pollutants in river water can be due to agricultural activities in catchment area due to industrial activitie..