What are the importance of DNA?

They are:

• It is the principal genetic material that carries genetic information from generation to generation.
• It controls all the biological activities of a cell. For example. protein synthesis.
• It can replicate and form its own carbon copies.
• It can synthesize RNA by the process of transcription.
• The mutation is caused by changes in the sequence of nitrogen bases in DNA.

Why is virus considered as biological puzzle or biological enigma?

Viruses act like non living substances outside the host cell however inside the host cell they show living characters, behaving like both living and nonliving things because of which they are also called biological enigma or puzzle.

What are the biological roles of water?

Water is a vital substance for life on Earth, and it plays numerous important biological roles in living organisms. Some of the key biological roles of water are:

1. Universal solvent: Water is an excellent solvent for many substances, both organic and inorganic. This means that it can dissolve and transport a wide range of nutrients and minerals necessary for the growth and survival of living organisms.

2. Medium for metabolic reactions: Many metabolic reactions in living organisms require water...