Answer:
The Bluetongue virus (BTV) core comprises a single-stranded RNA genome surrounded by two protein shells (capsids). The inner capsid is formed by the VP3 protein, which assembles into a T = 13 icosahedral lattices. The outer capsid is formed by the VP2 protein, which assembles into a T = 2 icosahedral lattices. The VP7 protein is not part of the capsid but forms a layer of trimers that lie at regular intervals along the outer surface of the core.
Step-by-step explanation: