Modes of nutrition কী?

A unicellular eukaryote feeds in one of three ways, or in two at once. Phototrophy: it has chloroplasts and makes its own organic matter from light and $\mathrm{CO_2}$ (green algae, diatoms, dinoflagellates). Phagotrophy: it engulfs particles — bacteria, other protists — into a food vacuole where lysosomal enzymes digest them (amoebae, ciliates, choanoflagellates). Osmotrophy: it absorbs dissolved molecules across its membrane, often after secreting enzymes outside (yeasts, many parasites). Mixotrophs such as Euglena photosynthesise in the light and eat in the dark. Prokaryotes cannot phagocytose: the wall forbids it, which is why a prokaryote never became a predator by engulfing.