Botany teacher brought a diseased plant in the classroom. Manoj identified the pathogen as a virus. Can you list any two symptoms of diseases, that helped him to identify the pathogen?

Resistance is the ability to prevent the pathogen from causing disease. Cite two examples for virus resistance plant.

From a fish market, you got a fish, on a close watching your friend says it is a cartilaginous fish. a) Which characters helped him to identify it as a cartilaginous fish. (any four characters.) b) Name the class it belongs.