Questions & Answers

Phagosomes and pinosomes are collectively called as-
(a) Residual bodies
(b) Autophagic bodies
(c) Digestive vacuoles
(d) Endosomes

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Hint: They are membrane-bound vesicles, developed via a complex family of processes known collectively as endocytosis, and found in virtually every animal cell's cytoplasm. The opposite of what happens during exocytosis or cellular secretion is the fundamental mechanism of endocytosis.

Complete answer:
Phagosomes can be characterized by the process known as phagocytosis as the vesicles that are produced around a particle or a substance that is engulfed by a phagocyte.
Whereas, pinosomes are the extracellular fluid-filled vesicle that is produced by pinching the cell membrane inward through the process called pinocytosis. They're called endosomes collectively.'
Endosomes are mainly organelles of intracellular sortation. They control the trafficking of proteins and lipids, including the plasma membrane Golgi, the trans-Golgi network (TGN) and the vacuoles/lysosomes, among other subcellular compartments of the secretory and endocytic pathway.
In cell biology, a phagosome is a vesicle formed through phagocytosis around a particle engulfed by a phagocyte. Skilled phagocytes include macrophages, dendritic cells (DCs) and neutrophils. The fusion of the cell membrane around a microorganism, a senescent cell, or an apoptotic cell forms a phagosome.
Pinosome: Inside a cell, a small fluid-filled vesicle (bubble). In the process of pinocytosis, pinosomes are formed in which tiny incuppings called caveolae (little caves) close at the cell surface and then pinch off to form pinosomes inside the cell cytoplasm.

Additional information: Residual bodies are vesicles containing indigestible materials in the lysosomal digestion process. Residual bodies are either secreted by exocytosis by the cell (this normally occurs only in macrophages) or become lipofuscin granules which remain indefinitely in the cytosol.
An organelle present in malaria-causing parasites is the food vacuole or digestive vacuole. It is the site of hemoglobin digestion and the development of the large hemozoin crystals that can be seen under a light microscope at the stage of the parasite life cycle where it resides inside a human (or other mammalian) red blood cell.
So, the correct answer is ‘(d) Endosomes’.

Note: Endosomes are produced by plasma membrane invagination and are activated by cell surface receptor activation (Hurley, 2008). The sorting of activated cell surface receptors to either the plasma membrane for further use or to the lysosome for degradation is regulated by endosomes.