What is the portion of the eye that allows light to pass into the posterior chamber?

Compare and contrast the adaptations of free-living flatworms and parasitic flatworms

Which organelle releases chemicals that break down large food particles into smaller ones?

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 .