Question

Define these terms:

(i) Incineration

(ii) Ozone hole

(iii) Ecosystem

Answer 1

(i)

Waste and its types:

1. Waste is something that after use has become useless. The waste is discarded.
2. Two types based on their degradation: Biodegradable and nonbiodegradable.

Incineration:

1. This is a waste disposal method.
2. In this, the organic waste is heated at a very high temperature (1000℃) to reduce it into ashes and gases.
3. The amount of ash left after burning is very less and therefore, the waste volume is greatly reduced.

(ii)

Ozone layer:

1. Ozone is a gas found in the stratospheric layer of the atmosphere at a height level of 20-50km from the surface.
2. This is a poisonous gas but protects the living organism from the harmful radiation from the sun by absorbing them.

Ozone hole:

1. The reduction in the amount of ozone causes the thinning of the ozone layer.
2. The place where the thickness of the ozone is very less is called an ozone hole.
3. Such a hole was observed over Antarctica.
4. ODS (ozone-depleting substances) reacts with ozone to break it down into its components.
5. The chances of these holes formation are more in the cold areas since more clouds provide more surface area for the reaction of the ozone and chemicals to occur here.

(iii)

Ecosystem:

1. An ecosystem is a self-sustaining unit of the environment that is composed of biotic and abiotic components.
2. There are different types of ecosystems in the environment.

Examples

1. Pond ecosystems
2. Desert ecosystems
3. Forest ecosystems.