Characteristics Protists are usually unicellular eukaryotic organisms. They live anywhere near a water body such as the ocean, lakes, swamps, etc. Multicellular protists dont have specialized tissues. They have nucleus and complex organelles Protist kingdom is made by any organism that didnt qualify to be animal, plant, or fungi. Exp: Amoeba, Euglena, Slime molds.
Nutrition Some protists such as flagellates feed by filtrating their water in order obtain food. Animal like protists expand their cell membrane around their prey forming a food vacuole and them “eat them” using endocytosis. Plant like protists are autotrophs, so they use photosynthesis in order to feed. Fungi like protists consume dead or decomposing matter.
Reproduction Protists reproduce both sexually and asexually by binary fission. Some species like the plasmodium have a more complex life cycle in which the can reproduce sexually and asexually.Growth Cells grow like bacteria and archae, except that it takes a longer to finish due the complexity of it.
Classification Chromalveolata: Some of them have cell walls, can do photosynthesis or have other similarities to plants. Alveolata: Alveolata group is known for havinf cortical alveoli and flattened vesicles. Excavata: Excavates dont have a regular have mitochondria. Usually the have more than two flagella. The closest example of excavata to multicellularism is the slime mold.
Rhizaria: Many have shell which makes up many of protist fossils. Arcaeplastida: Not all are prosists, only rhodophyta and glaucophyta. Unikonta: Not all are prosists, only Amebozoa and Choanozoa. This group features organisms such as amoebas
Pros and Cons Pros: Protists serve as food in the sea environment such as diatoms that form plankton (one of fish main food sources) which makes them a very important part of the underwater ecosystem. Cons: Some protists such as plasmodium can cause malaria, and the african typanosomiasis causes “sleeping sickness” that can lead to coma or death.