Before the widespread use of antibiotics, there were very low levels of antibacterial resistance. As antibiotic use has grown, so has the number of antibiotic resistant bacteria. WHY do you think this has occurred?

This is because antibiotic resistance can be caused by bacteria getting the ability to be unaffected by the antibiotics Also, people not taking their medication for the entire duration exposes the bacteria to the antibiotic and makes it stronger. Also, when people overuse antibiotics and mutations occur, the bacteria becomes antibiotic resistant.

answer; i believe the answer is (polygenic inheritance;

answer:

convection currents in the magma drive plate tectonics. heat generated from the radioactive decay of elements deep in the interior of the earth creates magma (molten rock) in the aesthenosphere. the aesthenosphere (70 ~ 250 km) is part of the mantle, the middle sphere of the earth that extends to 2900 km.