Q.Slime moulds are ___ protists

Slime Moulds

An Organism That Lives Two Lives

Slime moulds are among the strangest organisms you will meet in the plant-like-but-not-quite world of Protista. They are saprophytic — they feed on dead and decaying organic matter, especially bacteria, in moist soil, leaf litter, and rotting wood. They are not fungi, even though they eventually produce fruiting bodies that look a little like tiny mushrooms. They belong to Kingdom Protista, and their life cycle alternates between two very different forms depending on the conditions around them.

The Feeding Phase: Life as a Plasmodium

When conditions are favourable — plenty of moisture and food available — slime mould cells aggregate together and form a large, moving, multinucleate mass called a plasmodium. This is not a colony of separate cells sitting side by side; in true (plasmodial) slime moulds, the aggregated mass behaves as one continuous body containing many nuclei, without individual cell walls dividing it internally.

The plasmodium is visible to the naked eye — often bright yellow or orange — and can spread over several feet of decaying wood or leaf litter. It moves slowly, engulfing bacteria and organic debris as it feeds, growing larger as it goes.

The Reproductive Phase: Fruiting Bodies and Spores

When conditions turn unfavourable — the surroundings dry out or food becomes scarce — the plasmodium stops moving and differentiates. It forms fruiting bodies (sporangia) that resemble tiny stalked structures. Inside these, spores are produced.

Each spore has a tough, resistant wall that lets it survive extreme dryness, heat, and cold for long periods — sometimes years. When moisture returns, the spore germinates and releases new cells, and the cycle of feeding and aggregation begins again.

Two Related but Different Groups