Question

Tobacco mosaic virus is a tubular filament of size...

Answer 1

300×18 nm is the size

Hope it helps!

Answer 2

Tobacco mosaic virus size is $\bold{300 n m \times 20 n m}$ and it is a tubular filament.  

Tobacco mosaic virus is a single-stranded RNA virus that affects mostly the members of the family Solanaceae. Their infection pattern is mostly small patches like mosaic format and hence it got its name.  

Once it infects a plant it moves from one cell to another with the help of Plasmodesmata, for its effective entry it produces a protein called the P30 that enlarges the pores of the plasmodesmata.