Kingdom Prokaryotae (Monera): which organisms are included?

Introduction / Context:
Older five-kingdom classifications grouped all prokaryotes into Kingdom Monera (Prokaryotae). Modern systems prefer the three-domain model, but many exams still reference the legacy scheme.

Given Data / Assumptions:

• Prokaryotae = organisms lacking a membrane-bound nucleus and organelles.
• We compare Bacteria, Protozoa, and Fungi.
• Choose which belong in Prokaryotae.

Concept / Approach:
Bacteria (including cyanobacteria) are prokaryotic. Protozoa and Fungi are eukaryotic (true nucleus, organelles). Therefore, only Bacteria fit the Prokaryotae definition.

Step-by-Step Solution:

Verification / Alternative check:
Cross-check with cellular features: 70S ribosomes (cytosolic), circular chromosomes (bacteria), membrane-bound nucleus absent.

Why Other Options Are Wrong:
B: Protozoa have nuclei/organelles. C: Fungi have nuclei/organelles. D: Includes eukaryotes, thus incorrect.

Common Pitfalls:
Confusing cyanobacteria (photosynthetic bacteria) with “algae”; they are prokaryotes.

Final Answer:
Bacteria