Chapter 13: Our Environment

Ans: Substances that might be rotten and diminished to easier substances by microorganisms functioning on are known as biodegradable and people substances that can not be acted upon by microorganisms and aren't diminished into easier substances are units known as non-biodegradable substances. Examples of biodegradables - vegetable wastes, paper, cotton etc. On the opposite hand, materials that can not be rotten by the action of microorganisms/decomposers are non-biodegradable. For example- plastic, glass, polyethene etc.

 Ans: Two ways within which perishable substances would have an effect on the atmosphere area unit -

• Biodegradable waste is a substance that can be broken down easily and naturally by natural sources like water, oxygen, sun radiation, or microorganisms. 

• Biodegradable waste produces a foul smell and that’s why they result in pollution.

Ans: Non-biodegradable substances affect the environment in the following ways:

• They contaminate soil and water resources as they can't be rotten by microorganisms.

• These substances, if accidentally eaten by stray animals, will damage them and might even cause their death.

Ans: A trophic level is the steps in a food chain.

Consider the following scenario:

For example:

Grass - Trophic level I

Grasshopper - Trophic level II

Frog - Trophic level III

Ans: Decomposers eat decomposing and dead materials. They contribute to the clean-up of the environment.

Ans:  Oxygen in the form of ozone is a type of oxygen. Ozone's molecular formula is 03. In the atmosphere, it can be found in higher concentrations. It blocks the sun's damaging ultraviolet radiation from reaching the earth. UV rays have been linked to skin cancer, cataracts, and the extinction of plant and animal life.

Ans: The following methods can be taken to alleviate the trash disposal issue:

a. Reduce, reuse, and recycle as much as possible.

b. Use smart waste disposal techniques such as separate trash cans for different types of waste.

 Ans: (c) and (d)

Ans: (b)

Ans: (d)