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

Name the type of detritus that decomposes faster. List any two factors that enhance the rate of decomposition.

Write the different steps taken in humification and mineralisation during the process of decomposition.

Answer the following question.
Write any two places where methanogens can be found.

Substantiate with the help of one example that in an ecosystem mutualists 

are also one of the major causes of biodiversity loss. 

Answer the following question.
Write any two places where methanogens can be found.

Answer the following question:
Substantiate with the help of one example that in an ecosystem mutualists
(i) tend to co-evolve and
(ii) are also one of the major causes of biodiversity loss.

Suggest two practices giving one example of each, that help protect rare or threatened species.

GEAC stands for ______.

Water samples were collected at points A, B and C in a segment of a river near a sugar factory and tested for BOD level. The BOD levels of samples A, B and C were 400 mg/L, 480 mg/L and 8 mg/L respectively. What is this indicative of? Explain why the BOD level gets reduced considerably at the collection point C?

Which of the following is not a cause for loss of biodiversity?

What is common to lantana Eichhomia and African catfish?

The extinction of passenger pigeon was due to ______.

Which of the following statements is correct?

Which among the following forests is known as the "lungs of the planet earth"?

Which of these is NOT amongst the effects of loss of biodiversity?

Complete the following flow chart

The technology of biogas production from cow dung was developed in India largely due to the efforts of ______.

The residue left after methane production from cattle dung is ______.

Methanogens do not produce ______.

What would happen if our intestine harbours microbial flora exactly similar to that found in the rumen of cattle?