Tag: our environment - our concern

DDT (Dichlorodiphenyltrichloroethane) is an organochlorinated compound that is stable in nature. It is highly soluble in the fats of the living organism and so, it shows persistence in the food chain. It is seen that the level of DDT increases as the food chain progresses. It means, the primary consumers will have more DDT concentration than the producers, the secondary consumers will have more than primary consumers and so on. The highest concentrations will be seen in the top carnivore. This is because the consumers at the successive trophic level consume more than the previous level to fulfil the energy requirements. Due to this, DDT keeps on accumulating in the successive trophic levels in higher concentrations. This process is called the biomagnification.

DDT (Dichlorodiphenyltrichloroethane) is an organochlorinated compound that is stable in nature. It is highly soluble in the fats of the living organism and so, it shows persistence in the food chain. It is seen that the level of DDT increases as the food chain progresses. It means, the primary consumers will have more DDT concentration than the producers, the secondary consumers will have more than primary consumers and so on. The highest concentrations will be seen in the top carnivore. This is because the consumers at the successive trophic level consume more than the previous level to fulfil the energy requirements. Due to this, DDT keeps on accumulating in the successive trophic levels in higher concentrations. This process is called the biomagnification.

Plants are categorised into three groups based on their uptake of heavy metals - indicator, excluder and hyperaccumulator. Hyperaccumulator is a plant capable of growing in soils with high concentration of metals. They absorb through their roots and concentrate them in their tissues. The concentration is toxic to other species not adapted to grow on such soil. Arabidopsis belonging to the family Brassicaceae is a hyperaccumulator. Hence, the correct answer is 'Arabidopsis'.

DDT (Dichlorodiphenyltrichloroethane) is basically an organochlorine pesticide/insecticide. It was originally used for insecticides to prevent the crop from being damaged by insects, rodent, weeds etc. but due to its harmful effect it has been globally banned by "Stockholm convention on Persistent organic pollutant, 2001". By its nature, it is insoluble in water and shows high solubility in the fat of animals. They do not degrade easily and accumulate within the body of the organism in fat deposited portion. Due to their ability to show the biomagnification.

Biological magnification is also called as biomagnification and bioamplification. It occurs due to the increasing concentration of a toxic substance in the tissues of tolerant organisms that successively move up to higher levels in a food chain. The order of food chain for the given example is water followed by zoo plaktery followed by small fishes and lastly big fishes. It usually increase 2 to 10 folds in a food chain. Hence, the biomagnification of water, that is 0.0003 ppm is too less. Also, biomagnification of small fishes (0.2 ppm) should be ideally more than zoo plaktery (0.4 ppm). Hence, options A, B and D are incorrect. Big fishes having hightest biomagnification, that is 2 ppm.