The mast cells secrete the following substance

Which virus, for the first time, was synthesised in the form of non-living crystals

Which of the following is related to humoral immunity?

Damage to gastric mucosa is increased by alcohol plus

Secondary metabolites such as nicotine, strychnine and caffelne are produced by plants for their :

Mark the incorrect statement w.r.t. infection of Entamoeba histolytica