Which pollutant released into the air during refrigeration and air-conditioning is the greatest contributor to the depletion of ozone layer?

How much energy will be available to hawks in the food chain comprising hawk, snake, paddy and mice, if 10,000 J of energy is available to paddy from the sun?

What provides the energy which then flows through a food chain?

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?

GrassGrasshopper Frog Snake Hawk

Which of the following limits the number of trophic levels in a food chain?