Why is it so critically important to take penicillin at the prescribed time intervals when trying to eliminate a bacterial infection

I’m doing some practice exam questions for biology, and i’m not sure how to do these 3 parts to the question.

Connection compare and contrast genetic engineering to the process of natural selection. select all statements that are true.

Vaccines are weakened forms of disease causing microorganisms, which are given to patients to prevent disease. after the vaccine is administered, the immune system responds by creating a(n) to recognize the a.) antibody, antibiotic b.) antigen, antibody c.)antibiotic, antibody d.)antibody, antigen