NEET BIOLOGY

Detailed explanation-1: -Retroviruses are distinguished from other viruses by their ability to reverse-transcribe their RNA genomes into DNA intermediates by using the enzyme RT. The provirus DNA genome is then integrated into the host cell chromosomes by action of the viral enzyme integrase (IN).

Detailed explanation-2: -A type of virus that has RNA instead of DNA as its genetic material. It uses an enzyme called reverse transcriptase to become part of the host cells’ DNA. This allows many copies of the virus to be made in the host cells.

Detailed explanation-3: -How are retroviruses different from other viruses? Most RNA viruses reproduce by inserting RNA into the host cell. The RNA contains the instructions for making copies of the virus. A retrovirus is an RNA virus, but in the cell it is first converted into DNA and inserted into the host’s genes.

Detailed explanation-4: -The enzyme reverse transcriptase (RT) was discovered in retroviruses almost 50 years ago. The demonstration that other types of viruses, and what are now called retrotransposons, also replicated using an enzyme that could copy RNA into DNA came a few years later.

Detailed explanation-5: -Most retroviruses are spherical particles, approximately 100 nm in diameter, consisting of an internal protein core surrounded by an envelope of glycoproteins embedded in a lipid bilayer. The core contains several copies of reverse transcriptase bound to two identical single-stranded RNA molecules.