Question

specimen prep | simpler preparation; staining usually required | harsher preparation procedures
image formed by | light | selective absorption of electrons by the specimen.
image formed on | human eye can view real image directly by looking into the eyepiece | image is formed by projecting focussed image of specimen onto surface coated with electron - sensitive compounds
your science class is observing the organisms found in local pond water. you have discovered this paramecium and are hoping to observe how the paramecium injects food. your lab partner suggests using an electron microscope to see all the details in 3 - d. you disagree: you believe a light microscope must be used. using the table, support your decision to use a light microscope.
a the paramecium is not very small. it can easily be observed using the light microscope.
b you want to observe life processes. you cannot use an electron microscope to observe living specimens.
c in order to see the paramecium, you must stain the slide. you cannot stain a slide if using an electron microscope.
d the beam of electrons used in the electron microscope is too dangerous to be used in a high school classroom environment.

Explanation:

To determine the correct answer, we analyze each option:

• Option A: The size of the paramecium isn't directly supported by the table. The table focuses on preparation, image formation, etc., not size. Eliminate A.
• Option B: Electron microscopes require harsher preparation (from the table: "Harsher preparation procedures" for electron microscopes) which likely kills the specimen. To observe the life process (injecting food), a living specimen is needed, so light microscope (simpler prep, can view real image directly) is better. This matches the table's info.
• Option C: The table says light microscope usually requires staining, but there's no info that electron microscopes can't use stained slides. The key is about observing life processes, not staining. Eliminate C.
• Option D: The table doesn't mention safety in a classroom. The focus is on specimen preparation and image formation for observing life processes. Eliminate D.

Answer:

B. You want to observe life processes. You cannot use an electron microscope to observe living specimens.