Question

1. what does the diaphragm do? *

reflect light into the tube
holds up the entire microscope
adjusts the amount of light that passes through the microscope
supports the slide and allow light to pass through microscope

Explanation:

The diaphragm on a microscope controls the amount of light passing through by adjusting the aperture. It is not for reflecting light (that's the mirror or illuminator), holding up the microscope, or supporting the slide.

Answer:

Adjusts the amount of light that passes through the microscope