Science (English Medium) कक्षा १२ - CBSE Question Bank Solutions

The scientists believe that evolution is gradual. But extinction, part of evolutionary story, are 'sudden' and 'abrupt' and also group-specific. Comment whether a natural disaster can be the cause for extinction of species.

When we say "survival of the fittest", does it mean that

1. Those which are fit only survive, or
2. Those that survive are called fit

Comment.

Match the following list of bacteria and their commercially important products:

Choose the correct match:

Match the following list of bioactive substances and their roles:

Choose the correct match:

Which one of the following alcoholic drinks is produced without distillation?

What are fermentors?

Name a microbe used for statin production.

How has the discovery of antibiotics helped mankind in the field of medicine?

Why is distillation required for producing certain alcoholic drinks?

Write the most important characteristic that Aspergillus niger, Clostridium butylicum, and Lactobacillus share.

Give any two microbes that are useful in biotechnology.

Name any two industrially important enzymes.

Name an immune immunosupressive agent?

How was penicillin discovered?

Name the scientists who were credited for showing the role of Penicillin as an antibiotic?

How do bioactive molecules of fungal origin help in restoring good health of humans?

What roles do enzymes play in detergents that we use for washing clothes? Are these enzymes produced from some unique microorganisms?

What is a broad spectrum antibiotic? Name one such antibiotic.

Which bacterium has been used as a clot buster? What is its mode of action?

Which of the following enzymes catalyse the removal of nucleotides from the ends of DNA?