Question

the ________ causes the stage to move upward or downward. multiple choice coarse adjustment knob mechanical stage iris diaphragm objective lens

Explanation:

To solve this, we analyze each option:

• The coarse adjustment knob is used to move the stage (or the body tube) up and down for focusing, especially for initial focusing.
• A mechanical stage is used to hold and move the slide horizontally, not to move the stage vertically.
• An iris diaphragm controls the amount of light passing through the specimen, not stage movement.
• An objective lens is for magnification, not stage movement.

So the correct option is the one related to moving the stage vertically.

Answer:

A. coarse adjustment knob