Question

(a) From the following group of organisms create a food chain which is the most advantageous for Human beings in terms of energy. [Hawk, Rat, Cereal Plant, Goat, Snake, Human Being]

(b) State the possible disadvantage if the cereal plant is growing in soil rich in pesticides.

(c) Construct a food web using the organisms mentioned above.

Answer 1

a) 10% energy law:

1. This law was stated by Lindeman.
2. According to this law, only 10% of energy is transferred to the next trophic level in a food chain.
3. Therefore, the most advantageous food chain to human beings in terms of energy will be cereal plant → human being.

b) Biomagnification:

1. It is the accumulation of harmful substances such as DDT, pesticides, etc, in successive trophic levels.
2. Possible disadvantage of cereal growing in pesticide rich soil is that it will accumulate chemicals in the successive trophic levels.

c) The food chain including the above mentioned organisms will be:

Cereal plant → goat → human being → rat → snake → hawk.