Question

In some viruses, DNA is synthesised by using RNA as template. Such a DNA is called ______.

Options

• cDNA

• rDNA

• B-DNA

• A-DNA

Answer 1

In some viruses, DNA is synthesised by using RNA as template. Such a DNA is called cDNA.

Explanation:

In certain viruses, such as retroviruses, an enzyme called reverse transcriptase uses an RNA strand as a template to synthesise a matching DNA strand. This resulting molecule is called complementary DNA, or c-DNA, because its sequence is directly complementary to the original RNA. This process is the reverse of the normal flow of genetic information and allows the virus to integrate its genetic code into the host cell’s DNA.