Step 1: Understanding the Question:
The question requires us to evaluate four statements regarding biological classification and identify the correct one.
The statements cover Kingdom Protista, Cyanobacteria, Viruses, and Kingdom Fungi.
Step 2: Key Concepts and Approach:
We systematically analyze each statement based on Whittaker's Five Kingdom Classification system and general microbiology concepts.
Step 3: Detailed Explanation:
• Statement A: Kingdom Protista contains all unicellular eukaryotic organisms.
This includes Euglena (a euglenoid), Plasmodium (a protozoan sporozoan), and Amoeba (an amoeboid protozoan).
Hence, this statement is correct.
• Statement B: Cyanobacteria (blue-green algae) are photosynthetic prokaryotes.
While they perform oxygenic photosynthesis, they contain primitive prokaryotic cellular machinery, not "advanced characters of photosynthesis" which are characteristic of eukaryotic plants.
• Statement C: Viruses contain either DNA or RNA as their genetic material, never both.
Bacteriophages are viruses that infect bacteria and typically contain double-stranded DNA.
• Statement D: The cell wall of fungi is composed of chitin and beta-glucans.
Glycogen is the reserve food material stored inside fungal cells, not a structural component of their cell walls.
Step 4: Final Answer:
Statement A is correct as Kingdom Protista comprises unicellular eukaryotes such as Euglena, Plasmodium, and Amoeba.