Practice question

Food vacuole biogenesis in holozoic protists occurs through phagocytosis, a receptor-mediated active engulfment of particulate matter requiring cytoskeletal remodeling. Plasma membrane extends pseudopodia around prey, forming phagocytic cup, then internalizes phagosome which fuses with primary lysosomes containing acid hydrolases. Resultant secondary phagolysosome facilitates intracellular digestion producing nutrients. Pinocytosis involves liquid droplets, diffusion and osmosis are passive molecular transports incapable of capturing bacteria or algae. Hence bulk solid ingestion strictly requires actin-dependent phagocytic machinery characterizing Amoeba and ciliates. This feature underpins diagnostic microscopy, molecular phylogenetics and evolutionary understanding crucial for NEET, CBSE and competitive examinations requiring precise conceptual clarity.