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

In an experiment, DNA is treated with a compound which tends to place itself amongst the stacks of nitrogenous base pairs. As a result of which, the distance between two consecutive base increases, from 0.34nm to 0.44 nm. Calculate the length of DNA double helix (which has 2 × 109 bp) in the presence of saturating amount of this compound.

What would happen if histones were to be mutated and made rich in acidic amino acids such as aspartic acid and glutamic acid in place of basic amino acids such as lysine and arginine?

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?