The structural and functional unit of the environment is known as $......$

What is the layer located at an altitude of $50 \ km$ from the Earth's surface called?

Though the kulhads are made up of clay,which is an eco-friendly substance,their use has been discontinued in trains nowadays. Give reasons which lead to the discontinuance of this practice.

What is the process of the depletion of the ozone layer called?

Define a food web. State its significance for an ecosystem.

What are the two main components of our environment?