MICROANATOMY

Detailed explanation-1: -Iris Diaphragm controls the amount of light reaching the specimen. It is located above the condenser and below the stage.

Detailed explanation-2: -Field Diaphragm-an iris diaphragm, usually located on the base of the microscope that controls the amount of light that enters the condenser diaphragm. Fine Adjustment Knob-exactly positions the specimen at the focal point of the objective lens.

Detailed explanation-3: -Condenser: the lens located below the stage, which focuses light (from the illuminator) through the specimen being observed. Most microscopes have a movable condenser allowing its distance from the specimen to be adjusted using the condenser knob and condenser alignment screws.

Detailed explanation-4: -Answer and Explanation: The amount of light entering a microscope may be adjusted by regulating the diaphragm, therefore the answer is b. The diaphragm, also called the iris diaphragm, adjusts the size and intensity of the cone of light that reaches the specimen.