Mr. Chapman Biology 20

 Funguslike protists are decomposers. A decomposer is an organism that breaks down dead or decaying organisms.  Decomposers are also known as saprotrophs. Note the similarity in names between this form of nutrition and others we have learned, such as heterotroph and autotroph.  Decomposers play a critical role in the ecosystem as they recycle nutrients such as carbon and nitrogen from dead organisms back into the soil.

Different types of funguslike protists The bottom right picture is a plasmodial slime mold. The bottom left picture is a cellular slime mold.

 Funguslike protists used to be classified as members of Kingdom Fungi, but are no longer classified this way due to the fact that during part of their life cycle they are motile.  Slime molds are eukaryotic organisms that have both funguslike and animal-like traits.  Two types of slime molds: plasmodial slime molds and cellular slime molds.

 Live most of their lives as a large, single mass of cytoplasm with many nuclei. Can grow to be as large as 1 meter or more in diameter.  Moves like a giant amoeba, extending pseudopods and creeping over decaying matter to absorb nutrients. WqWKJKQ&NR=1

 Commonly found on the underside of logs and on dead leaves.  When food or moisture are in short supply, plasmodial slime molds develop resistant, reproductive structures that produce spores.  These spores are often able to move on their own, either creeping like an amoeba or developing flagella (if water is present). Spores can recombine to form new plasmodial slime molds. 

 Commonly found in soil, release spores that become single amoeba-like cells.  Cells are able to swarm together and form a slug- like body that moves as if it were one organism. However, it is still many organisms as their cell membranes do not fuse.  This structure is called a pseudoplasmodium, meaning “fake plasmodium.”

 Common in freshwater habitats.  Not all are decomposers, some exist as parasites on other living organisms, such as plants or fish.  The mold first appears as a cotton-like coating, but eventually causes deep wounds and can lead to death of its host.