Advertisements
Advertisements
प्रश्न
What are trophic levels? Give an example of a food chain and state the different trophic levels in it.
Advertisements
उत्तर १
The various links or steps in a food chain at which the transfer of food and energy takes place are called trophic levels.
The producers form the first trophic level as they manufacture food. The primary consumers form the second trophic level, the secondary consumers form the third, and the tertiary consumers form the fourth trophic level.
In the above fig. The grass is the producer, which is eaten by the grasshopper, known as the primary consumer. Then the grasshopper is eaten by a shrew, a secondary consumer, and lastly shrew is eaten up by an owl, a tertiary consumer.
उत्तर २
The various steps in food chain at which transfer of food energy takes place are called trophic levels.
Example: Food chain operating in a grassland.
Grass → Insects → Frogs → Snakes
- Grass → 1 st trophic level
- Insects → 2 nd trophic level
- Frogs → 3 rd trophic level
- Birds → 4 th trophic level
APPEARS IN
संबंधित प्रश्न
What will be the amount of energy available to the organisms of the 2nd trophic level of a food chain if the energy available at the first trophic level is 10,000 joules?
Why are green plants called producers?
Fill in the following blank with suitable word :
In nature, all green plants are............ whereas animals are consumers.
Fill in the following blank with suitable word :
A series of organisms, each of which feeds on the next organism, the beginning of which is a green plant, is called a .............
What is the difference between the food habits of organisms belonging to the first and the third trophic levels? Give one example each of the organisms belonging to these two trophic levels.
Which of the following statement is incorrect?
In the food chain comprising of a snake, grass, insect, and frog, the secondary consumer is :
(a) insect
(b) snake
(c) frog
(d) grass
The following is a food chain that ends with human :
How does this food chain differ form a usual food chain involving human such as : plants → goat → human?
What would happen to the number of rabbits and grass plants if the number of foxes decreased?
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 |
Write the percentage of energy transferred from autotrophs to the next level in a food chain.
In a food chain consisting of grass, frog, bird and insects, where will the concentration of the harmful chemicals be maximum?
What provides the energy which then flows through a food chain?
(a) glucose
(b) oxygen
(c) respiration
(d) sunlight
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
Most of the water surface of a lake is covered with algae. This algae is part of the food chain which also includes small fish, bird, larvae and big fish. Which of the following will obtain the maximum energy?
(a) big fish
(b) bird
(c) larvae
(d) small fish
In addition to wheat plants, a crop field ecosystem has organisms such as snake, peacock, eagle and mice. If the wheat plants are sprayed with pesticides periodically, which of the following will have the minimum concentration of pesticides in the body?
(a) snake
(b) eagle
(c) mice
(d) peacock
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.
The process of accumulation of harmful chemical substances like pesticides, in the body of living organisms at each trophic level of a food chain is known as ______.
______ obtained energy from the chemical breakdown of dead organisms.
What is Autotrophs?
