Which of the following is an example of a unicellular prokaryotic organism?

• A. Escherichia coli
• B. Plasmodium falciparum
• C. Paramecium caudatum
• D. Saccharomyces cerevisiae

Answer: (A)

Verified step by step guidance

1. Understand the characteristics of prokaryotic organisms: Prokaryotes are unicellular organisms that lack a nucleus and membrane-bound organelles. Their DNA is typically circular and found in a region called the nucleoid.
2. Identify the characteristics of Escherichia coli: E. coli is a well-known bacterium that is unicellular and lacks a nucleus, fitting the description of a prokaryotic organism.
3. Consider the characteristics of Plasmodium falciparum: This organism is a protozoan parasite, which is eukaryotic, meaning it has a nucleus and membrane-bound organelles, thus not fitting the prokaryotic description.
4. Evaluate Paramecium caudatum: This is a unicellular eukaryotic organism, specifically a ciliate protozoan, which has a nucleus and other organelles, so it is not prokaryotic.
5. Analyze Saccharomyces cerevisiae: Commonly known as yeast, this is a unicellular eukaryotic organism used in baking and brewing, possessing a nucleus, and therefore not a prokaryote.