Question

Genetic material of retrovirus is:
A. ss RNA
B. ss DNA
C. ds RNA
D. ds DNA

Answer 1

Hint: A retrovirus is a type of virus that have RNA as genetic material and whenever, it wants to infect its host, it makes a DNA copy of its genome and then insert it to the host cell to integrate its DNA copy with host genome.

Complete answer:
Viruses are a large community that helps humans as well as cause a lot loss to human property or directly humans. These small creatures can live in plants, animals, bacteria, in very hot springs as well as in dry and cold conditions. They are everywhere.
As, life cycle of viruses is very small. So, chances or rate of mutation is very high for the viruses. It is possible that we develop a vaccine for the viruses and it gets mutated and again can infect deadly.
But viruses sometimes may be beneficial for us. When we do genetic engineering. In producing genetically engineered organisms or plants. So, these small creatures are friend as well as foe.
Some viruses have the unique property of having RNA as their genetic material. The genetic material can be single-stranded (ss) or double-stranded (ds) RNA genomes in viruses. Retrovirus means it behaves opposite to the natural way of genetics, that is, generally DNA goes to RNA and then RNA goes to protein. But in retrovirus, RNA reverse-transcribed to DNA.
All the organisms expect viruses to have double stranded DNA as their genetic material thus, to integrate with the host genome without coming to the notice of the host, it is necessary that the viral genome should be double-stranded. Thus, before integration into host viruses perform reverse-transcription.
So, we can conclude that retrovirus which perform reverse-transcription must be single-stranded RNA.

Option ‘A’ is the correct answer. 

Note: The scientific community considers viruses as living and non-living both, because when they are outside the host, they are dead but as soon as they enter their host, they start replicating means they are alive. So, to understand their mechanism of working is quite difficult.