Answer:
Tetracycline was discovered in the 1940s and is effective against both gram-positive and gram-negative bacteria. Tetracycline is an antibiotic which kills the bacteria by inhibiting the synthesis of protein.
Tetracycline act by inhibiting the process of translation by preventing the binding of aminoacyl-charged tRNA to the A site of the ribosome.
Since the aminoacyl charged tRNA does not bind the A site therefore the process of translation is inhibited.