Question

Largest known RNA virus is

• A. TMV
• B. T${}_1$ phage
• C. Citrus tristeza
• D. $\varphi \times$ 174

Answer 1

The correct option is C Citrus tristeza

Citrus tristeza virus (CTV) is a virus that causes the most economically damaging disease to Citrus. CTV is phloem-limited and the largest of the known plant viruses. CTV is a flexuous rod virus with dimensions of 2000 nm long and 12 nm in diameter. The CTV genome is 19.3 kb long and consists of a single strand of positive sense RNA enclosed by capsid proteins. The size of its genome makes CTV one of the largest RNA viruses known.

So, the correct answer is 'Citrus tristeza'.