How could it be treated?

After getting the slide and microscope ready, stella is eager to see the microscopic pond water specimen! she crouches around her microscope and aligns her eye with the microscope’s eyepiece. but she's only able to see a bright white light. at this point, no specimens or cells are visible on stella's pond water slide. after taking a moment to collect her thoughts, stella realizes she can't see any lifeforms because .

Apart of an ecosystem that can restrict the growth of a population is referred to as

How can antibodies "remember" a particular bacterial invader or "antigen" on that invader?