Read the following and answer any four questions from: (i) to (v).

In any given ecosystem, all living organisms are linked in a systematic chain with respect to their mode of manufacturing food/ feeding habits. This sequential interlinking of organisms involving transfer of food energy from producers through a series of organisms with repeated eating and being eaten is called the food chain. A food chain may have 3-4 trophic levels.

(i). Which of the following statements regarding food chain is incorrect?

1. It is a single straight pathway through which food energy travels in the ecosystem.
2. It adds adaptability and competitiveness to the organisms.
3. Presence of isolated food chains adds to instability of the ecosystem.
4. Food chain binds up inorganic nutrients of the ecosystem.

(ii). Consider the following food chain.

Grass → A → Frog → Snake → Eagle.

Which of the following can be placed at A?

1. Grasshopper.
2. Rabbit.
3. Phytoplankton.
4. Rat.

(iii). Select the correct food chain.

1. Aquatic plants → Tadpole → Water beetle → Pike → Perch.
2. Grass → Grasshopper → Snake → Frog → Eagle.
3. Grass → Rabbit → Wild cat → Tiger.
4. Zooplankton → Phytoplankton → Small fish → Fish.

 

(iv). Food chains are sustained by producers and .

1. Herbivores.
2. Carnivores.
3. Omnivores.
4. Decomposers.

 

(v). Select the incorrect statement.

1. Food chain may terminate at level of herbivore.
2. Food chain is always straight.
3. Food chain may have 3-5 trophic levels.

d. in a food chain, 80 to 90% of potential energy is lost as heat, at each transfer.