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प्रश्न
DDT was sprayed in a lake to regulate breeding of mosquitoes. How would it affect the trophic levels in the following food chain associated with a lake? Justify your answer.
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उत्तर
- DDT being a non- biodegradable pesticide will enter the food chain from the first trophic level i.e Plankton.
- Non – biodegradable pesticides accumulate progressively at each trophic level. This phenomenon is known as biological magnification.
- HAWK will have the highest level of pesticide.
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संबंधित प्रश्न
Will the impact of removing all the organisms in a trophic level be different for different trophic levels? Can the organisms of any trophic level be removed without causing any damage to the ecosystem?
In the following food chain, 100 J of energy is available to the lion. How much energy was available to the producer?
Plants → Deer → Lion
Explain how the pesticides enter a food chain and subsequently get into our body.
Consider the food chain :
Grass → Deer → Lion
What will happen if all the lions are removed from the above food chain?
In the food chain comprising of a snake, grass, insect, and frog, the secondary consumer is :
(a) insect
(b) snake
(c) frog
(d) grass
What would happen to the number of grass plants and foxes if the number of rabbits increased?
What would happen to the number of grass plants and foxes if the number of rabbits decreased?
Human body is made up of five important components, of which water is the main component. Food, as well as potable water, are essential for every human being. The food is obtained from plants through agriculture. Pesticides are being used extensively for a high yield in the fields. These pesticides are absorbed by the plants from the soil along with water and minerals and from the water bodies these pesticides are taken up by the aquatic animals and plants. As these chemicals are not biodegradables, they get accumulated progressively at each trophic level. The maximum concentration of these chemicals gets accumulated in our bodies and greatly affects the health of our mind and body.
- Why is the maximum concentration of pesticides found in human beings? (1)
- Give one method which could be applied to reduce our intake of pesticides through food to some extent. (1)
- Various steps in a food chain represent:
- Food web
- Trophic level
- Ecosystem
- Biomagnification (1)
- With regard to various food chains operating in an ecosystem, man is a:
- Consumer
- Producer
- Producer and consumer
- Producer and decomposer (1)
Observe the food web and answer the questions given below:
Why do all food chains start with plants?
Which group of organisms are not constituents of a food chain?
- Grass, lion, rabbit, wolf
- Plankton, man, fish, grasshopper
- Wolf, grass, snake, tiger
- Frog, snake, eagle, grass, grasshopper
