CBSE Class 10 Science 2022 · Paper 31(B)/5 · Question 13

Trophic level: each step or level of a food chain at which the transfer of food (energy) takes place is called a trophic level. Food chain: Plants $\to$ Rats $\to$ Snakes $\to$ Hawks (plants at the first trophic level, rats at the second, snakes at the third and hawks at the fourth). Energy: by the ten per cent law, about $10\%$ of the energy at one level is made available to the next. From $1000$ J at the first level, the second level gets $100$ J, the third $10$ J and the fourth $1$ J. So $1$ J of energy will be made available to the hawks at the fourth trophic level.