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प्रश्न
In a food chain, the third trophic level is always occupied by :
(a) carnivores
(b) herbivores
(c) decomposers
(d) producers
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उत्तर
carnivores
The third trophic level is always occupied by carnivores. The first trophic level is occupied by producers, the second by herbivores and the fourth by decomposers.
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संबंधित प्रश्न
What are trophic levels? Give an example of a food chain and state the different trophic levels in it.
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 one or two word for the following statement/definition :
Organisms which depend on the producers for food either directly or indirectly
In a food chain, the initial organism is usually :
(a) photosynthetic
(b) herbivore
(c) saprophytic
(d) parasitic
Which of the following is not a producer?
(a) grass
(b) zooplankton
(c) phytoplankton
(d) paddy
A food chain occurring in the sea which provides food for many people can be written as :
phytoplankton → zooplankton → X → Y
Name one phytoplankton.
Write the percentage of energy transferred from autotrophs to the next level in a food chain.
Name the process in which a harmful chemical enters the food chain and gets concentrated at each trophic level.
In a food chain consisting of grass, frog, bird and insects, where will the concentration of the harmful chemicals be maximum?
The following statement is true or false :
Only 10 per cent of the light energy given by the sun is available for transfer at each higher trophic level in a food chain.
Fill in the following blank with suitable word :
Grass → ........... → Human
'If we excessively use pesticides to protect the crops from diseases, then it may cause long-term damage to mankind'. Justify this statement.
| 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
Write the importance of the food chain.
Food chains are very important for the survival of most species.
Matter and energy are two fundamental inputs of an ecosystem. Movement of:
______ are organisms that are able to produce their own organic food.
Define – Heterotrophs.
Study the picture given below showing three food chains (a), (b) and (c) and answer the following questions:
- Name the type of ecosystems that exist in food chains (b) and (c).
- The first trophic level in all food chains is producers. Why? What percentage of solar energy do these producers capture for their use?
- Why are the arrows shown in the diagram in one direction only and not vice versa? Justify.
