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Consider a simple aquatic ecosystem like a lake which consists of algae, small fish and large fishes. It was found that the lake water was contaminated with a low concentration of a non-biodegradable pesticide, DDT. Based on this ecosystem, answer the following questions :
(a) In which organism will the concentration of the pesticide DDT be the highest ? Name and explain the phenomenon.
(b) Why is the flow of energy in a food chain always unidirectional ?
(a) In which organism will the concentration of the pesticide DDT be the highest ? Name and explain the phenomenon.
(b) Why is the flow of energy in a food chain always unidirectional ?
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• In large fishes (1 Mark)
• Biological magnification: progressive accumulation of non-biodegradable harmful chemicals at each trophic level. (1 Mark)
As energy flows progressively through the various trophic levels it is no longer available to the previous level / Energy available at each trophic level get diminished progressively due to loss of energy at each level. (1 Mark)
• Biological magnification: progressive accumulation of non-biodegradable harmful chemicals at each trophic level. (1 Mark)
As energy flows progressively through the various trophic levels it is no longer available to the previous level / Energy available at each trophic level get diminished progressively due to loss of energy at each level. (1 Mark)