Question

A researcher at the Centers for Disease Control (CDC) is studying a protozoan and a bacteria that lives inside it. Using a light microscope, which of the following organelles will she observe in both organisms?

A) Nucleus
B) Ribosomes
C) Endoplasmic reticulum
D) All of the above are correct.
E) Both (a) and (b)

Answer 1

Both a protozoan (a eukaryote) and a bacterium (a prokaryote) contain ribosomes, which are observable with a light microscope; however, only the protozoan has a nucleus. Thus, both nucleus and ribosomes are seen in protozoa, while only ribosomes are seen in bacteria.

Step-by-step explanation:

The researcher studying a protozoan and a bacteria using a light microscope will observe ribosomes in both organisms. While bacteria, which are prokaryotic cells, lack a nucleus and endoplasmic reticulum, they do contain ribosomes, which are necessary for protein synthesis. Similarly, protozoa, which are eukaryotic cells, also contain ribosomes as well as a nucleus and endoplasmic reticulum. Therefore, the correct answer to the question 'Which of the following organelles will she observe in both organisms?' is E) Both (a) and (b), meaning both the nucleus and ribosomes are observable in the protozoan, but only ribosomes are observable in the bacteria.