Question

All of the following are true about phagocytosis EXCEPT:

• A. Amoeba and other protozoans live their life by it
• B. Used to ingest particles < 0.5 microns in size
• C. Used to ingest particles > 0.5 microns in size
• D. Digestion occurs within phagolysosomes

Hint:

Sub-half-micron uptake belongs to pinocytosis, not phagocytosis.

Answer 1

The Correct Option is B

Step 1: Phagocytosis ("cell eating") is the engulfment of large solid particles, typically those greater than about 0.5 micron, such as bacteria, dead cells, and debris.
Step 2: Pinocytosis ("cell drinking") handles fluid and very small particles smaller than about 0.5 micron, so ingesting particles < 0.5 micron is a feature of pinocytosis, not phagocytosis.
Step 3: Evaluate the options. Amoeba and other free-living protozoans indeed feed by phagocytosis (true). Ingesting particles > 0.5 micron is correct for phagocytosis (true). After engulfment, the phagosome fuses with a lysosome to form a phagolysosome where digestion occurs (true).
Step 4: The only false statement is that phagocytosis ingests particles < 0.5 micron.
Conclusion: The exception is option B, matching the printed key.