A one-celled animal organism that contains no cell walls is called a ___
A. virus.
B. protozoa.
C. prion.
D. fungi.
B. protozoa.
The correct answer is B. protozoa.
The correct answer is B. protozoa.
To arrive at this answer, we need to understand the characteristics of the given options:
A. A virus is not a one-celled organism. Viruses are considered non-living particles that require a host cell to survive and reproduce. They do not have their own cellular structure.
B. Protozoa are one-celled organisms that possess a cell membrane instead of a cell wall. They are eukaryotic, meaning they have a true nucleus and other organelles. Protozoa have more complex structures than bacteria, which have cell walls.
C. Prions are misfolded proteins that can cause infectious diseases. They do not qualify as one-celled organisms.
D. Fungi are multicellular organisms. They have cell walls made of chitin and are not one-celled organisms.
Based on this analysis, the correct answer is B. protozoa, as it is the only option that meets the criteria of being a one-celled organism without a cell wall.