Why does ozone hole form over Antarctica? How will enhanced ultraviolet radiations affect us?

Write the name of the organism that is referred to as the 'Terror of Bengal'.

State the cause of accelerated eutrophication.

Since October 02, 2014 'Swachh Bharat Abhiyan' has been launched in our country.

(a) Write your views on this initiative giving justification.

(b) As a biologist name two problems that you may face while implementing the programme in your locality.

(c) Suggest two remedial methods to overcome these problems.

Name any two sources of e-Wastes and write two different ways for their disposal.

How have human activities caused desertification? Explain. 

How does algal bloom destroy the quality of a fresh water body? Explain.

89.

Why is Eichhornia crassipes nicknamed as Terror of Bengal? 

By the end of 2002 the public transport of Delhi switched over to a new fuel. Name the fuel. Why is this fuel considered better? Explain.