The concentration of an insecticide in the animals of a species is called:

Which of the following is $NOT$ a bioindicator of water pollution?

Biological magnification refers to

Spraying of $DDT$ on crops produces pollution of ...

Burning of fossil fuels affects which of the following cycles?

Choose the correct option regarding the following statements:
$(1)$ $CO_2$ contribution in global warming is $60\%$.
$(2)$ Greenhouse effect occurs due to deforestation.
$(3)$ Due to the greenhouse effect,the present average temperature at the surface of the Earth is $15^oC$.
$(4)$ The amount of $DDT$ in small fish is $0.05\ ppm$.