18. You are staining bacterial samples for identification. As you place this sample to view under the microscope, the bacterial shape you observe is:
Answer: D
Cocci are the bacterial shape observed under the microscope.
Cocci are spherical-shaped bacteria, and this particular shape is what you would see when observing the stained bacterial sample under the microscope.
A) Bacilli
Bacilli are rod-shaped bacteria. If the sample observed under the microscope exhibited this elongated shape, it would be classified as bacilli, not cocci. Therefore, this option is incorrect in the context of identifying the observed bacterial shape.
B) Spirochetes
Spirochetes are characterized by their spiral shape, resembling a corkscrew. This shape would not be consistent with the spherical appearance of cocci. Thus, this option is incorrect for the observed sample.
C) Vibrio
Vibrio bacteria are comma-shaped and exhibit a curved rod structure. Since the question specifies that the observed shape is cocci, this option does not apply, making it incorrect.
D) Cocci
Cocci refer to spherical bacteria, which aligns perfectly with the observation made under the microscope. This option is correct as it directly describes the shape being identified.
Conclusion
Cocci is the definitive answer as it accurately describes the spherical shape observed in the stained bacterial sample. The other options—bacilli, spirochetes, and vibrio—refer to different bacterial shapes that do not match the observation, reinforcing that cocci is the correct identification.