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प्रश्न
What is a 'food web'? Show its formation.
उत्तर
The inter-connected food chains operating in an ecosystem that establish a network of relationships among various species comprise a food web.
A food web is formed by many food chains operating together. A food web operating in a grassland is shown in the figure.
Five food chains are possible in this food web, which are as follows.
1) Grass→ Grasshopper→ Frog→ Hawk
2) Grass→Grasshopper→ Rat→ Fox
3) Grass→ Rabbit→ Fox
4) Grass→ Rat → Snake→Hawk
5) Grass→Rat →Hawk
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संबंधित प्रश्न
Write down a food chain in the sea.
Write down a food chain with five links in it.
Which of the following 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
In the food chain comprising of a snake, grass, insect, and frog, the secondary consumer is :
(a) insect
(b) snake
(c) frog
(d) grass
'If we excessively use pesticides to protect the crops from diseases, then it may cause long-term damage to mankind'. Justify this statement.
In the food chain given below, if the amount of energy available at fourth trophic level is 5 kJ, what was the energy available at the producer level?
Grass → Grasshopper → Frog → Snake → Hawk
(a) 500 kJ
(b) 50 kJ
(c) 5000 kJ
(d) 5 kJ
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.
Your mother always thought that fruit juices are very healthy for everyone. One day she read in the newspaper that some brands of fruit juices in the market have been found to contain certain level of pesticides in them. She got worried as pesticides are injurious to our health.
(a) How would you explain to your mother about fruit juices getting contaminated with pesticides?
(b) It is said that when these harmful pesticides enter our body as well as in the bodies of other organisms they get accumulated and beyond a limit cause harm and damage to our organs. Name the phenomenon and write about it.
In an ecosystem, herbivores represent ______.
Natural agents like ______ are the decomposition factors breaking complex forms into simpler units.
