What is the molecular formula of ozone?

What will happen if the deer is missing in the food chain given below?
Grass $\to$ Deer $\to$ Tiger

Which group of organisms are not constituents of a food chain?
$(i)$ Grass,lion,rabbit,wolf
$(ii)$ Plankton,man,fish,grasshopper
$(iii)$ Wolf,grass,snake,tiger
$(iv)$ Frog,snake,eagle,grass,grasshopper

Which trophic level is occupied by primary carnivores in a food chain?

State a way to prevent the accumulation of harmful chemicals in our bodies.

During heavy rain in a village,rainwater carried excessive fertilizers to a pond. How will it affect the fish population in the pond in the long run?