Science (English Medium) इयत्ता १२ - CBSE Question Bank Solutions for Biology

What is common to the species shown in figures A and B?

A	B

What is common to the species shown in figures A and B?

A	B

Of the four major causes for the loss of biodiversity (Alien species invasion, habitat loss and fragmentation, over-exploitation and co-extinctions which according to you is the major cause for the loss of biodiversity? Give reasons in support.

Discuss one example, based on your day-to-day observations, showing how loss of one species may lead to the extinction of another.

What criteria should one use in categorizing a species as threatened?

List any two major causes other than anthropogenic causes of the loss of biodiversity.

Explain the concept of "co-extinction" by taking two examples.

How can you, as an individual, prevent the loss of biodiversity?

Though the conflict between humans and wildlife started with the evolution of man, the intensity of conflict has increased due to the activities of modern man. Justify your answer with suitable examples.

World’s most problematic aquatic weed is ______.

Which of the following exhibits biomagnification?

Which one of the following impurities is easiest to remove from wastewater?

Algal blooms impart a distinct colour to water due to ______.

What is cultural eutrophication?

Name an industry which can cause both air and thermal pollution and as well as eutrophication.

What is an algal bloom?

What do you understand by biomagnification?

What are the three major kinds of impurities in domestic wastewater?

Is it true that if the dissolved oxygen level drops to zero, the water will become septic. Give an example which could lower the dissolved oxygen content of an aquatic body.

How has DDT caused decline in bird population?