Assertion: all bacteria are closely related to each other
Reason: drugs that block one of these life processes in one member of the group is likely to be effective against many other members of the group.
Both assertion and reason are true and reason is correct explanation of assertion.
Antibiotics generally block the biosynthetic pathways of the microbes/bacteria. Certain antibiotics get rid of the bacteria by killing it, like penicillin. They generally disrupt the formation of the cell wall or cell contents of the bacteria. The other kind of antibiotics inhibits the multiplying action of the bacteria.