This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Bacteriology, Subject name: Microbiology
Protein A of Staphylococcus aureus is a pa of 
Select and explain. 
A. Cell wall, B. Genome, C. Limiting membrane, D. Plasmid
A: Cell wall
Answer: A: Cell wall 
Explanation: Protien A, is the cell surface protien, present in most S.aureus strains, has many biological propeies, including chemotactic, antiphagocytic and anti-complementary effects. IT also induces platelet damage and hypersensitivity. Ref: Textbook of Ananthanarayan and paniker's; 10th Edition; Pg:203