This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
Tetracycline inhibits protein synthesis by ? 
Select and explain. 
A. Inhibiting initiation and causing misreading of mRNA, B. Binding to 30 S subunit and inhibits binding of aminoacyl tRNA, C. Inhibiting peptidyl transferase activity, D. Inhibiting translocation
B: Binding to 30 S subunit and inhibits binding of aminoacyl tRNA
Answer: B: Binding to 30 S subunit and inhibits binding of aminoacyl tRNA 
Explanation: Ans. is 'b' i.e., Binding to 30S Subunit and inhibits binding of aminoacyl tRNA o Tetracycline interact with small ribosomal subunits, blocking access of aminoacyl- tRNA to the mRNA-ribosome complex. o Tetracyclines bind to 30 S subunit of ribosome.