Question

Which among the following is not a prokaryote ?

• A. Saccharomyces
• B. Nostoc
• C. Mycobacterium
• D. Oscillatoria

Answer 1

The Correct Option is A

The question asks which among the following options is not a prokaryote. To answer this, we need to understand the classification of organisms based on their cell structure: prokaryotes and eukaryotes.

Definitions and Explanation:

• Prokaryotes: These are organisms whose cells lack a true nucleus and other membrane-bound organelles. Examples include bacteria and cyanobacteria (blue-green algae).
• Eukaryotes: These organisms have cells with a true nucleus and membrane-bound organelles. This group includes animals, plants, fungi, and protists.

Let's analyze the given options:

1. Saccharomyces: This is a genus of fungi, specifically yeast. Saccharomyces cerevisiae, commonly known as baker's yeast, is a well-known eukaryote. Therefore, Saccharomyces is not a prokaryote.
2. Nostoc: It is a genus of cyanobacteria, which are photosynthetic bacteria and fall under prokaryotes.
3. Mycobacterium: This is a genus of bacteria, which are prokaryotes.
4. Oscillatoria: This is also a type of cyanobacteria, thus a prokaryote.

Based on this analysis, the option that is not a prokaryote is Saccharomyces as it is a eukaryotic fungus.

Hence, the correct answer is: Saccharomyces.