When looking through a compound light microscope, which part is typically used to adjust the focus of the specimen at high magnification?

• A. Diaphragm
• B. Coarse adjustment knob
• C. Fine adjustment knob
• D. Stage clip

Answer: (C)

Verified step by step guidance

1. Understand the function of each part of the compound light microscope: The diaphragm controls the amount of light passing through the specimen, the coarse adjustment knob is used for large-scale focusing at low magnification, the fine adjustment knob is used for precise focusing at high magnification, and the stage clip holds the slide in place.
2. Recognize that at high magnification, small adjustments are necessary to bring the specimen into clear focus without overshooting or damaging the slide.
3. Identify that the fine adjustment knob is specifically designed for making these small, precise adjustments to the focus of the specimen.
4. Eliminate other options based on their functions: The diaphragm does not adjust focus, the coarse adjustment knob is too imprecise for high magnification, and the stage clip does not contribute to focusing.
5. Conclude that the fine adjustment knob is the correct part to use for focusing the specimen at high magnification.