<prompt> Pseudomembrane over tonsil and pharynx is caused byGram positive baciliGram negative baciliSS RNA virusCatalase negative cocci  <response>: Pseudomembrane is formed in diphtheria, which is caused by Corynebacterium diphtheria, which is a gram-positive bacillus Ref: Harshmohan textbook of pathology; 7th edition 