Question

Rous Sarcoma Virus contains
A. Single stranded DNA
B. Double stranded DNA
C. Single stranded RNA
D. Double stranded RNA

Answer 1

RSV or Rous Sarcoma Virus is a retrovirus, which causes sarcoma in chickens. RSV is a class VI enveloped virus with a positive sense RNA genome having a DNA intermediate.

Complete Answer:
A retrovirus is a type of virus that can insert a copy of its RNA genome into the DNA of the host cell. They carry the genetic blueprint in the form of ribonucleic acid (RNA). Retro virus is named after the enzyme reverse transcriptase. Reverse transcriptase transcribes the RNA into DNA. Another example for retrovirus is the Human Immunodeficiency Virus (HIV).

Now, let's look at the options for a correct answer:
- Option A: Single stranded DNA are mostly found in Anelloviridae and bidnaviruses. Rous sarcoma virus does not contain single stranded DNA. Therefore, this is the incorrect option.
- Option B: Double stranded DNA is the major form of genetic material in most organisms. But is not seen in the Rous sarcoma virus. Therefore, this is the incorrect option.
- Option C: Rous sarcoma virus has a positive sense single stranded RNA genome. RSV has a reverse transcriptase enzyme which converts RNA into cDNA then this cDNA gets incorporated into the host genome and causes sarcoma. Therefore, this is the correct option.
- Option D: Fully developed double stranded RNA is found in many plant, animal and bacterial viruses. dsRNA is also found in cells infected with single-stranded RNA viruses. Therefore, this is the incorrect option.

Thus, the correct option is C) Single stranded RNA.

Note: RSV has four genes:
1. Gag – Encodes capsid proteins
2. Pol – Encodes reverse transcriptase
3. Env – Encodes the envelope gene
4. Src – Encodes a tyrosine kinase that attaches phosphate groups to the amino acid tyrosine in host cell proteins