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प्रश्न
Define decomposers.
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उत्तर
Micro-organisms that break down the complex organic compounds present in dead plants and animals and their products, such as faeces and urine, into simpler substances are called decomposers.
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संबंधित प्रश्न
Why are green plants called producers?
Fill in the following blank with suitable word :
In nature, all green plants are............ whereas animals are consumers.
Can the organisms of any trophic level be removed without causing any damage to the ecosystem? Will the impact of removing all the organisms in a trophic level be different for different trophic levels?
A student went to study a local pond. In one part of the pond she noticed tadpoles scraping at some pond weed. In another part she saw a water beetle holding a tadpole in its jaws.
(a) Construct a food chain for the pond.
(b) How many links are there in this chain?
Write a common food chain of a pond ecosystem having four links.
Give one example of a simple food chain.
Organisms of a higher trophic level which feed on several types of organisms belonging to a number of lower trophic levels constitute the ______.
In a food chain consisting of grass, frog, bird and insects, where will the concentration of the harmful chemicals be maximum?
Fill in the following blank with suitable word :
Grass → ........... → Human
Fill in the following blank with suitable word :
Plants → Antelope → ............
What is meant by bioconcentration of pesticides
Which of the following limits the number of trophic levels in a food chain?
(a) insufficient food supply from producer level
(b) decrease in energy at higher trophic levels
(c) increase in the number of organisms at higher trophic levels
(d) accumulation of harmful chemicals at higher trophic levels
A food chain comprises of cat, seed-eating bird, plants, and dog. The organism which will have the maximum concentration of harmful pesticides coming through the food chain is most likely to be :
(a) cat
(b) plants
(c) dog
(d) seed-eating bird
The ten per cent law is associated with
(a) transfer of energy from various trophic levels to decomposers in a food chain
(b) transfer of ATP energy into muscular energy
(c) transfer of chemical energy from one organism to another
(d) transfer of sun's energy to the organisms called producers.
| 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: (1)
- Food web
- Trophic level
- Ecosystem
- Biomagnification
- With regard to various food chains operating in an ecosystem, man is a: (1)
- Consumer
- Producer
- Producer and consumer
- Producer and decomposer
Bacteria and fungi are called decomposers.
Which of the following is a logical sequence of food chain?
Differentiate between herbivores and carnivores.
Assertion (A): The energy which passes to the herbivores does not come back to autotrophs.
Reason (R): The flow of energy in a food chain is unidirectional.
