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प्रश्न
Why are there rarely more than five links (or five organisms) in a food chain?
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उत्तर
There are rarely more than five links (or five organisms) in a food chain because, according to the 10 per cent law, only 10 per cent of the available energy is transferred to the next trophic level. So, at the higher trophic levels, the amount of energy is reduced to such an extent that it becomes insufficient for an organism to sustain itself.
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संबंधित प्रश्न
Why are green plants called producers?
What are the various steps of food chain called?
Which organisms belong to third and fourth trophic levels in the food chain comprising the following?
Rats, Plants, Hawk, Snakes
A food chain represents a unidirectional flow of X. What is X?
Define decomposers.
Write a common food chain of a pond ecosystem having four links.
In a food chain, the initial organism is usually :
(a) photosynthetic
(b) herbivore
(c) saprophytic
(d) parasitic
The sea water contains water beetles, tadpole, fish and weeds.
Which organisms in the food chain are herbivore, and carnivores?
What would happen to the number of grass plants and foxes if the number of rabbits increased?
Match the terms given in column I with the terms given in column II and column III having the same meaning :
| Column I | Column II | Column III |
| (1) Secondary consumer | Herbivore | 1st trophic level |
| (2) Primary consume | Autotroph | 3rd trophic level |
| (3) Producer | Carnivore | 4th trophic level |
| (4) Tertiary consumer | Large carnivore | 2nd trophic level |
Fill in the following blank with suitable word :
Plants → Antelope → ............
Which common pesticide has accumulated in human body in considerable amounts?
The surface of water in a lake appears green due to a layer of tiny free-floating organisms X on its surface. The lake water also contains organisms like water beetle, fish and tadpole. The sun shines over the lake water and provides energy for the functioning of this lake ecosystem.
(a) What could organisms X be?
(b) Write a food chain comprising of all the four organisms mentioned.
(c) What is the general name of the food chains like the one written above?
(d) Name (i) secondary consumer (ii) producer (iii) tertiary consumer, and (iv) primary consumer, in the above food chain.
(e) If the tertiary consumer gets 0.2 J of energy from the secondary consumer, then how much energy was radiated by the sun to the producer?
A food chain consists of fish, larvae, phytoplanktons and birds. The level of pesticides in water in which the fish, larvae and phytoplanktons live is quite high.
Write the food chain comprising all the organisms mentioned above.
| 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
Arrange the following in a correct sequence and form a food chain
Human → Insect → Algae → Fish
Give some examples for Biodegradable and Non-biodegradable waste.
| S. No. | Biodegradable waste | Non-biodegradable waste |
| 1. | Food Waste | Plastic Bottles |
| 2. | ||
| 3. | ||
| 4. | ||
| 5. |
If 100 J energy is available at the producer level in a food chain then the energy available to the secondary consumer will be ______.
In an ecosystem, herbivores represent ______.
______ obtained energy from the chemical breakdown of dead organisms.
