Which type of microscope is best suited for observing the presence or absence of trichomes on a specimen?

• A. Light microscope (bright-field)
• B. Transmission electron microscope
• C. Phase-contrast microscope
• D. Scanning tunneling microscope

Answer: (A)

Verified step by step guidance

1. Step 1: Understand the nature of the specimen and the feature to be observed—in this case, trichomes, which are hair-like structures on the surface of plants or microorganisms, visible at the micrometer scale.
2. Step 2: Review the capabilities of each microscope type: a bright-field light microscope uses visible light to illuminate the specimen and is suitable for observing surface structures like trichomes at moderate magnification.
3. Step 3: Consider the transmission electron microscope (TEM), which provides very high resolution but is best for viewing internal ultrastructural details rather than surface features.
4. Step 4: Evaluate the phase-contrast microscope, which enhances contrast in transparent specimens but is primarily used for observing live cells and internal structures rather than surface appendages like trichomes.
5. Step 5: Recognize that the scanning tunneling microscope (STM) is designed for imaging surfaces at the atomic level, typically of conductive materials, and is not practical for biological specimens like trichomes.