One way in which protists are considered primitive is that they are mostly unicellular, and the ones that are multicellular do not organize their cells into specialized tissues. However, protists have been evolving just as long as other life on Earth and are not necessarily primitive beings.Know More
Scientists originally thought protists were the most primitive organisms alive, and their forms had remained stable throughout the billions of years life has existed on Earth. It is now known that the similarities between protists are actually superficial, and they are actually many different groups of creatures that have been changing and adapting for billions of years. Some protists are derived from more complex ancestors. Therefore, their seemingly primitive organization may not be representative of what truly primitive life forms are like.
Protists are defined not in terms of their supposed primitiveness but according to an inability to place them comfortably within the plant, animal or fungal kingdoms. Many scientists do not recognize the category at all as biologically valid, because protists are so diverse and have multiple origins.Learn more about Biology
Protists live in lakes, rivers, oceans, ponds and wet sediments. Since they are microscopic organisms, they can live in just about any part of the world that has traces of water to support their life.Full Answer >
The types of protists, which are eukaryotes, that aren't animals, fungi or plants include euglenoza, alevolates, stramenopiles, red algae, slime molds and choanoflagellates. The alevolate group includes ciliates, sporozoans and dinoflagellates. The stramenopile group includes diatoms, golden algae, green algae and water molds.Full Answer >
Some harmful protists include plasmodium, gregarines, haemosporidia and coccidians. Others include babesia, toxoplasma, adeleorina and some forms of amoeba. Some of these protists are parasites on invertebrates such as gastropods while others are parasites on vertebrates such as humans.Full Answer >
All protists are eukaryotic, meaning they feature a cellular structure with nuclei to contain their genetic material. Also called protozoans, which means "first animals," all protists prefer a moist environment and are found where there is perpetually moist soil or in freshwater and saltwater bodies of water.Full Answer >