Question

(02.02 mc)
what is a limitation of using electron microscopes to view specimens?
a you cannot view transparent specimens because of the microscope’s low resolution.
b electron beams are dangerous and can only be sparingly used.
c you cannot view live specimens because the necessary preparation kills cells.
d resolution is weak and cannot make out details of very small specimens.

question 2 (3 points)
(02.02 mc)
what would be the best microscope to view living single - celled organisms in a sample of pond water?
a transmission electron microscope
b scanning electron microscope
c compound light microscope
d dissecting microscope

Explanation:

Question 1

• Option a: Electron microscopes have high resolution, so this is incorrect.
• Option b: Electron beams aren't "sparingly used" due to danger in the context of specimen viewing limitations; the main issue is specimen preparation, not beam usage frequency.
• Option c: Electron microscopes require specimen preparation (like fixing, dehydrating) that kills cells, so live specimens can't be viewed. This is correct.
• Option d: Electron microscopes have very high resolution, so this is incorrect.

• Option a: Transmission electron microscopes require killing and preparing specimens, can't view live organisms.
• Option b: Scanning electron microscopes also need specimen preparation that kills cells, not suitable for live organisms.
• Option c: Compound light microscopes can be used to view live, single - celled organisms in pond water as they don't require harsh preparation that kills cells and can magnify enough to see such organisms.
• Option d: Dissecting microscopes have lower magnification and are used for larger specimens or dissection, not for viewing single - celled organisms in pond water.

Answer:

c. You cannot view live specimens because the necessary preparation kills cells.

Question 2