Protists are a varied category of eukaryotic creatures that are unicellular or multicellular, and can be free-living or parasitic. They have a simple cellular structure, with a nucleus and other membrane-bound organelles, and are capable of a wide variety of metabolic operations, including as photosynthesis, digesting, and locomotion.31 Jan 2022 ... ABSTRACT. Protists and other eukaryotes are present in diverse terrestrial and aquatic environments. They can easily be collected from local ...The protist cell is a eukaryotic cell. Eukaryotic cells have a true nucleus and membrane-covered cell organelles (parts within the cell) like chloroplast, Golgi body, mitochondria, etc. Some ...The apicomplexan protists are so named because their microtubules, fibrin, and vacuoles are asymmetrically distributed at one end of the cell in a structure called an apical complex (Figure 28.2.6 28.2. 6 ). The apical complex is specialized for entry and infection of host cells. Indeed, all apicomplexans are parasitic.Most protist diseases in humans are caused by protozoa. Protozoa make humans sick when they become human parasites. Trypanosoma protozoa cause Chagas disease and sleeping sickness. Giardia protozoa cause giardiasis, and …Protist is the international forum for reporting substantial and novel findings in any area of research on protists. The criteria for acceptance of manuscripts are scientific excellence, significance, and interest for a broad readership. Suitable subject areas include: molecular, cell and developmental biology, biochemistry, systematics and phylogeny, and ecology …76. Introduction to Protists. Figure 1: Protists range from the microscopic, single-celled (a) Acanthocystis turfacea and the (b) ciliate Tetrahymena thermophila, both visualized here using light microscopy, to the enormous, multicellular (c) kelps (Chromalveolata) that extend for hundreds of feet in underwater “forests.” (credit a ... Protista. The Protista is a large complex grouping of mostly unicellular eukaryotic organisms. They are morphologically diverse and can be found in most terrestrial, aquatic, and marine habitats as free-living forms and as parasites of other protists, of fungi, and of plants and animals. 9 Apr 2012 ... Life on Earth 007 - Protists Paul Andersen surveys organisms in the protists. He reviews the diversity found within the domain Eukarya and ...Learn for free about math, art, computer programming, economics, physics, chemistry, biology, medicine, finance, history, and more. Khan Academy is a nonprofit with the mission of providing a free, world-class education for anyone, anywhere. 7 Nov 2020 ... The primary goals of P10K are to generate the whole-genome sequences (WGSs) of 10,000 protists and create new reference genomes for the ...Here's a list of similar words from our thesaurus that you can use instead. Noun. A diverse taxonomic group of microscopic eukaryotic organisms. Protista. protoctist. Protoctista. “The biologist studied the protist under the microscope, fascinated by its complex structures and diverse characteristics.”. Find more words!16 May 2020 ... First of all they are Eukaryotic. This means that their genetic material is packaged inside a nucleous within their cell, as opposed to ...9 May 2022 ... In this video I explain characteristics of the kingdom Protista.If you have an organism that is eukaryotic, in other words has a nucleus and ...Giardia lamblia, single-celled parasite of the order Diplomonadida, the cause of the diarrheal illness giardiasis.Similar to other diplomonads, the cells of Giardia lamblia have two nuclei and eight flagella. G. lamblia cells are further distinguished by the presence of minute organelles known as mitosomes. The parasite can survive outside of host …Protists include the single-celled eukaryotes living in pond water (Figure 10.1.1 10.1. 1 ), although protist species live in a variety of other aquatic and terrestrial environments, and occupy many different niches. Not all protists are microscopic and single-celled; there exist some very large multicellular species, such as the kelps.Many of the protist species classified into the supergroup Excavata are asymmetrical, single-celled organisms with a feeding groove “excavated” from one side. This supergroup includes heterotrophic predators, photosynthetic species, and parasites. Its subgroups are the diplomonads, parabasalids, and euglenozoans.This page titled 8: Protists and Fungi is shared under a CK-12 license and was authored, remixed, and/or curated by CK-12 Foundation via source content that was edited to the style and standards of the LibreTexts platform; a detailed edit history is available upon request.3 Oct 2021 ... frontoventral cirri: of spirotrich ciliates, a group of cirri between the anterior portion of the right-marginal cirral row (or the right body ...Protists are eukaryotic, mostly unicellular, and mostly aquatic. 'Eukaryotic' means that they have cells with a nucleus and membrane-bound organelles and are similar to the cells that make up our bodies. Because they are eukaryotic, protists fall within the domain Eukarya. Most protists are unicellular, meaning they are only made of one cell. …The protists are microscopic eukaryotic organisms that typically live as single cells but exhibit a wide array of cellular behaviors. There is such a variety of lifestyles within the protists that ...Protist definition: any of various one-celled organisms, classified in the kingdom Protista, that are either free-living or aggregated into simple colonies and that have diverse reproductive and nutritional modes, including the protozoans, eukaryotic algae, and slime molds. See examples of PROTIST used in a sentence.9. Plant-Like Protists Euglenoids Plant-like and Animal-like Euglenophyta Cyst forming (frozen seas) Golden Algae (carotenoids) Chrysophyta dinoflagellates Bioluminescence (red tide) Dinoflagellata Examples Characteristics Phylum. 10. Plant-Like Protists.protist definition. any organism that is not a plant, animal, fungus, or a prokaryote. what is a protist? eukaryotes that are not members of the kingdoms Plant, Animal, or Fungi. formal name of a protist?Protists are a very large group of phylogenetically distinct eukaryotes that can be unicellular, multicellular, heterotrophic, autotrophic, or mixotrophic. The share many similarities with but are ...protist , Any member of a kingdom (Protista) of diverse eukaryotes, including algae, protozoans, and lower fungi ( see fungus ). Most are single-celled organisms, though the algae tend to be multicellular. Many can move, mainly by using flagella ( see flagellum), cilia ( see cilium), or footlike extensions (pseudopodia). Termites eat the wood & the flagellate digests the wood. They reproduce asexually by dividing. First it does conjugation which is an exchange of DNA and then divides which is binary fission. Study with Quizlet and memorize flashcards containing terms like What is one thing all protists have in common, What are some traits to protists, What are ...The protists called slime molds can act like animals or like fungi (such as mushrooms). Sometimes slime molds move around as unicellular creatures, as protozoans do. But at other times slime mold cells gather together. They form a slimy layer that moves across forest floors or other surfaces. This slime feeds on decaying plants and other living ... The Kingdom Protista includes three main groups of protists: protozoa (animal-like protists), algae (plant-like protists), and slime molds and water molds (fungus-like protists). Protozoa are usually motile and display animal-like behaviors, while algae are typically photosynthetic and exhibit plant-like features.3 Oct 2021 ... frontoventral cirri: of spirotrich ciliates, a group of cirri between the anterior portion of the right-marginal cirral row (or the right body ...Interesting Facts about Protists. Many protists act as pathogens to humans. This means they cause diseases. The disease malaria is caused by the protist Plasmodium falciparum. If an amoeba is cut in half, the half with the nucleus will survive, while the other half will die. The word "pseudopod" comes from Greek words meaning "false feet." Seaweed is a type …Paramecium ( / ˌpærəˈmiːʃ ( i) əm / PARR-ə-MEE-sh (ee-)əm, /- siəm / -see-əm, plural "paramecia" only when used as a vernacular name) [2] is a genus of eukaryotic, unicellular ciliates, commonly studied as a model organism of the ciliate group. Paramecium are widespread in freshwater, brackish, and marine environments and are ... protist: [noun] any of a diverse taxonomic group and especially a kingdom (Protista synonym Protoctista) of eukaryotic organisms that are unicellular and sometimes colonial or less often multicellular and that typically include the protozoans, most algae, and often some fungi (such as slime molds).Some protists have different types of modes of nutrition. Mode of Reproduction. Protists reproduces both by sexual and asexual means of reproduction. Types of reproduction in protists are discussed below: Asexual Reproduction; This is the most common method of reproduction in the members of the protist kingdom. Asexual reproduction takes place in …The protist cell is a eukaryotic cell. Eukaryotic cells have a true nucleus and membrane-covered cell organelles (parts within the cell) like chloroplast, Golgi body, mitochondria, etc. Some ...The sperm find and fertilize the eggs by detecting chemicals, called pheromones, released by the female gametophytes. Once fertilized, the egg develops into a sporophyte that takes over the female ...Protists are a complex and diverse group of living organisms. This lesson provides information about protists including general characteristics, classification, …Many of the protist species classified into the supergroup Excavata are asymmetrical, single-celled organisms with a feeding groove “excavated” from one side. This supergroup includes heterotrophic predators, photosynthetic species, and parasites. Its subgroups are the diplomonads, parabasalids, and euglenozoans.Protists are organisms that are part of the biological kingdom called the protista. These organisms are not plants, animals, bacteria, or fungi. Protists are a very diverse group of organisms. They are basically all the organisms that don't fit into the other groups. Protists as a group have very little in common. protist. Protists are mostly single-celled, microscopic organisms that are not considered to belong to the animal, plant, or fungi kingdoms. Instead, they are classified as members of the kingdom Protista. Protists are eukaryotes, which means that they have a true nucleus and organelles. Thousands of species of protists exist, and scientists ...Jan 11, 2021 · Protists are mostly unicellular (one-celled) eukaryotes. A few protists are multicellular (many-celled) and surprisingly large. For example, kelp is a multicellular protist that can grow to be over 100-meters long (Figure below). Multicellular protists, however, do not show cellular specialization or differentiation into tissues. 31 Jan 2022 ... ABSTRACT. Protists and other eukaryotes are present in diverse terrestrial and aquatic environments. They can easily be collected from local ...Jan 17, 2024 · amoeba, any of the microscopic unicellular protozoans of the rhizopodan order Amoebida. The well-known type species, Amoeba proteus, is found on decaying bottom vegetation of freshwater streams and ponds. There are numerous parasitic amoebas. Of six species found in the human alimentary tract, Entamoeba histolytica causes amebic dysentery. 29 Oct 2016 ... Protists are a group of loosely connected, mostly unicellular eukaryotic organisms that are not plants, animals or fungi.These protists exist in freshwater and marine habitats, and are a component of plankton, the typically microscopic organisms that drift through the water and serve as a crucial food source for larger aquatic organisms. Figure 23.3.4 23.3. 4: The dinoflagellates exhibit great diversity in shape. Protist s are an informal grouping of eukaryotes that are not plants, animals, or fungi. Some algae are protists and others are bacteria; all protozoa are examples of protists. Algae (singular: alga) are mostly made up of protists that can be either unicellular or multicellular and vary widely in size, appearance, and habitat (Figure 1.15). Algal protists are …Oct 11, 2022 · What are protists and why should I care? In this video we delve into Kingdom Protista to find out more about protists and their vital role in health, the env... 16 May 2020 ... First of all they are Eukaryotic. This means that their genetic material is packaged inside a nucleous within their cell, as opposed to ...Protists are a food source for many animals. Phytoplankton is one of the sole food sources for whales, some of the largest creatures on Earth. Zooplankton are fed on by various sea creatures including shrimp and larval crabs. Humans even harvest various protists for food. Seaweed is an algae, which is considered a plant-like protist.9 May 2022 ... In this video I explain characteristics of the kingdom Protista.If you have an organism that is eukaryotic, in other words has a nucleus and ...Unicellular; group is polyphyletic. Four supergroups of protists. Excavata, SAR clade, Archaeaplastida, Unikonta. Excavata. Supergroup; Excavated groove on the side of it's body. Diplomonad. Super group Excavata; two nuclei and multiple flagella; this causes giardia. Parabasilids. Supergroup Excavata; Sexually transmitted protist; causes ...Members of this group range from small single cells to much larger colonies. As their name suggests, they contain green chlorophyll. Green algae are diverse and ...Many of the protist species classified into the supergroup Excavata are asymmetrical, single-celled organisms with a feeding groove “excavated” from one side. This supergroup includes heterotrophic predators, photosynthetic species, and parasites. Its subgroups are the diplomonads, parabasalids, and euglenozoans. Unicellular; group is polyphyletic. Four supergroups of protists. Excavata, SAR clade, Archaeaplastida, Unikonta. Excavata. Supergroup; Excavated groove on the side of it's body. Diplomonad. Super group Excavata; two nuclei and multiple flagella; this causes giardia. Parabasilids. Supergroup Excavata; Sexually transmitted protist; causes ...There are three main groups within the protists that are defined by how they acquire their nutrition: animal-like protists, plant-like protists, and fungus-like protists. Animal-like protists are ...13 Sept 2023 ... Kingdom Protista – Characteristics, Classification, Importance, Examples ... Kingdom Protista is one of the five kingdoms that classify various ...May 4, 2019 · Examples of protists include algae, amoebas, euglena, plasmodium, and slime molds. Protists that are capable of photosynthesis include various types of algae, diatoms, dinoflagellates, and euglena. These organisms are often unicellular but can form colonies. They also contain chlorophyll, a pigment which absorbs light energy for photosynthesis. Protist - Ecology, Habitats, Diversity: The distribution of protists is worldwide; as a group, these organisms are both cosmopolitan and ubiquitous. Every individual species, however, has preferred niches and microhabitats, and all protists are to some degree sensitive to changes in their surroundings. The availability of sufficient nutrients and water, as well as …Protists possess characteristics that make them “like” multi-cellular organisms, yet they lack certain properties to be classified as animal, plant or fungus. The presence of a nucleus in all protist organisms means they are all eukaryotic. The three primary classifications in the Protista Kingdom and subsequent phylum include:The protist then transports its cytoplasm into the pseudopod, thereby moving the entire cell. This type of motion, called cytoplasmic streaming, is used by several diverse groups of protists as a means of locomotion or as a method to distribute nutrients and oxygen.Protist - Ecology, Habitats, Diversity: The distribution of protists is worldwide; as a group, these organisms are both cosmopolitan and ubiquitous. Every individual species, however, has preferred niches and microhabitats, and all protists are to some degree sensitive to changes in their surroundings. The availability of sufficient nutrients and water, as well as …9. Plant-Like Protists Euglenoids Plant-like and Animal-like Euglenophyta Cyst forming (frozen seas) Golden Algae (carotenoids) Chrysophyta dinoflagellates Bioluminescence (red tide) Dinoflagellata Examples Characteristics Phylum. 10. Plant-Like Protists.dinoflagellate, (division Dinoflagellata), any of numerous one-celled aquatic organisms bearing two dissimilar flagella and having characteristics of both plants and animals. Most are marine, though some live in freshwater habitats. The group is an important component of phytoplankton in all but the colder seas and is an important link in the food …Examples of Protists. Few example of kingdom protista are: Amoebas: Unicellular, motile protozoans that move by extending pseudopods and feed on microorganisms. Paramecium: Ciliated, unicellular protozoans with a characteristic slipper-like shape. Euglena: Unicellular organisms that can be both autotrophic (photosynthetic) …29 Oct 2016 ... Protists are a group of loosely connected, mostly unicellular eukaryotic organisms that are not plants, animals or fungi.Figure 23.4 A. 1: Protists and aquatic organisms: Virtually all aquatic organisms depend directly or indirectly on protists for food. Protists do not only create food sources for sea-dwelling organisms. Certain anaerobic parabasalid species exist in the digestive tracts of termites and wood-eating cockroaches where they contribute an essential ...The Protista group contained animals that were eukaryotic but not readily classified as a plant, animal, or fungi. So, the group isn't organized around common characteristics but is a convenient ...A protist (/ ˈ p r oʊ t ɪ s t /) is any eukaryotic organism (one with cells containing a nucleus) that is not an animal, plant, or fungus.The protists do not form a natural group, or clade, since they exclude certain eukaryotes with whom they share a common ancestor; but, like algae or invertebrates, the grouping is used for convenience.In some systems of …Protist - Diversity, Unicellular, Microscopic: Protists vary greatly in organization. Some are single-celled; others are syncytial (coenocytic; essentially a mass of cytoplasm); and still others are multicellular. (While protists may show multicellularity, they are never multitissued.) They may manifest as filaments, colonies, or coenobia (a type of colony with a fixed number of interconnected ... Protist cells may be enveloped by animal-like cell membranes or plant-like cell walls. Others are encased in glassy silica-based shells or wound with pellicles of interlocking protein strips (Figure \(\PageIndex{4}\)). The pellicle functions like a flexible coat of armor, preventing the protist from being torn or pierced without compromising ...This HD dramatic video choreographed to powerful music introduces the viewer/student to the microscopic kingdom of the Protists. It is designed as a motivati...Hence, protist is not a phylogentically useful term. Rather, it is a term of convenience that describes an assemblage of often distantly related organisms lumped together as a matter of ecological utility. The protists do have lineages that are properly organized to represent evolutionary relationships. Some clades, which are groups of ...protist. (prō′tĭst) n. Any of numerous eukaryotic organisms that are not fungi, plants, or animals and are chiefly unicellular or colonial. Protists that are multicellular do not have cells differentiated into tissues. The protists include the protozoans, certain algae, oomycetes, and slime molds. pro·tis′tan (-tĭs′tən) adj. & n.Protists use various methods for transportation. (a) Paramecium waves hair-like appendages called cilia to propel itself. (b) Amoeba uses lobe-like pseudopodia to anchor itself to a solid surface and pull itself forward. (c) Euglena uses a whip-like tail called a flagellum to propel itself. But, both consists of membrane-bound organelles like Golgi apparatus and ER. Their chromosomes are organized into a nucleus as well. Some protists are autotrophs, while others are heterotrophs. Fungi are heterotrophs. The main difference between protists and fungi is that protists are mainly unicellular organisms whereas fungi are …Mar 6, 2021 · Protist Reproduction. Protists have complex life cycles. Many have both asexual and sexual reproduction. An example is a protist called Spirogyra, a type of algae, shown Figure below. Protistology is a scientific discipline devoted to the study of protists, a highly diverse group of eukaryotic organisms. All eukaryotes apart from animals, plants and fungi are considered protists. Its field of study therefore overlaps with the more traditional disciplines of phycology, mycology, and protozoology, just as protists embrace mostly unicellular …protist. (prō′tĭst) n. Any of numerous eukaryotic organisms that are not fungi, plants, or animals and are chiefly unicellular or colonial. Protists that are multicellular do not have cells differentiated into tissues. The protists include the protozoans, certain algae, oomycetes, and slime molds. pro·tis′tan (-tĭs′tən) adj. & n.Most protist diseases in humans are caused by protozoa. Protozoa make humans sick when they become human parasites. Trypanosoma protozoa cause Chagas disease and sleeping sickness. Giardia …. Protists are eukaryotic, mostly unicellular, and mostly aquatic. 'Eukaryotic' means that they have cells with a nucleus and membrane-bound organelles and are similar to the cells that make up our bodies. Because they are eukaryotic, protists fall within the domain Eukarya. Most protists are unicellular, meaning they are only made of one cell. …Protists exhibit many forms of nutrition and may be aerobic or anaerobic. Protists that store energy by photosynthesis belong to a group of photoautotrophs and are characterized by the presence of chloroplasts. Other protists are heterotrophic and consume organic materials (such as other organisms) to obtain nutrition. The protist then transports its cytoplasm into the pseudopod, thereby moving the entire cell. This type of motion, called cytoplasmic streaming, is used by several diverse groups of protists as a means of locomotion or as a method to distribute nutrients and oxygen.Protists. Protists are unicellular eukaryotes that are not plants, animals, or fungi. Algae and protozoa are examples of protists. Algae (singular: alga) are plant-like protists that can be either unicellular or multicellular (Figure \(\PageIndex{4}\)). Their cells are surrounded by cell walls made of cellulose, a type of carbohydrate. Protist definition: any of various one-celled organisms, classified in the kingdom Protista, that are either free-living or aggregated into simple colonies ...5 Mar 2021 ... Summary · Kingdom Protista includes all eukaryotes that are not animals, plants, or fungi. · Kingdom Protista is very diverse. It consists of ...Mar 6, 2021 · Protist Reproduction. Protists have complex life cycles. Many have both asexual and sexual reproduction. An example is a protist called Spirogyra, a type of algae, shown Figure below. protist. Protists are mostly single-celled, microscopic organisms that are not considered to belong to the animal, plant, or fungi kingdoms. Instead, they are classified as members of the kingdom Protista. Protists are eukaryotes, which means that they have a true nucleus and organelles. Thousands of species of protists exist, and scientists ...16 Jul 2017 ... Protists (the members of Kingdom Protista) are unicellular eukaryotic organisms. They are mixture of plant, animals and fungi of two kingdom ...Mar 13, 2016 · For convenience, the term protist is still often used to refer to all eukaryotes that aren’t animals, plants or fungi. Most protists are extremely small microorganisms. They are mostly single-celled organisms and can have cells as small as prokaryotic cells between 0.5-2 µm. There is a huge diversity of protists.
What are protists and why should I care? In this video we delve into Kingdom Protista to find out more about protists and their vital role in health, the env.... Lovin on me jack harlow
Protist - Evolution, Fossils, Eukaryotes: In the case of most protist lineages, extinct forms are rare or too scattered to be of much use in evolutionary studies. For certain taxa, fossil forms are abundant, and such material is useful in an investigation of their probable interrelationships, though only at lower taxonomic levels within those groups themselves.Protists. Protists are unicellular eukaryotes that are not plants, animals, or fungi. Algae and protozoa are examples of protists. Algae (singular: alga) are plant-like protists that can be either unicellular or multicellular (Figure \(\PageIndex{4}\)). Their cells are surrounded by cell walls made of cellulose, a type of carbohydrate. A protist, or a member of the kingdom Protista, is a member of a group that is defined really more by what it is does not include (i.e., organisms that are clearly animals, plants or fungi of some sort) than by what it does. As a result, its membership is broad and the criteria somewhat hazy.Protists come in a wide variety of different forms and may be classified as animal-like, plant-like, or fungus-like, depending on their characteristics. Animal-like protists are called protozoa (meaning ‘first animal’). What is the importance of protists in human life? Importance. Protists are responsible for a variety of human diseases including …9 May 2022 ... In this video I explain characteristics of the kingdom Protista.If you have an organism that is eukaryotic, in other words has a nucleus and ...protist: [noun] any of a diverse taxonomic group and especially a kingdom (Protista synonym Protoctista) of eukaryotic organisms that are unicellular and sometimes colonial or less often multicellular and that typically include the protozoans, most algae, and often some fungi (such as slime molds).Protists are very simple organisms made of one cell and are usually very tiny, and they don't fit into the category of animal, plant, fungus or bacteria. To unlock this lesson you must be a Study ...Some protists have different types of modes of nutrition. Mode of Reproduction. Protists reproduces both by sexual and asexual means of reproduction. Types of reproduction in protists are discussed below: Asexual Reproduction; This is the most common method of reproduction in the members of the protist kingdom. Asexual reproduction takes place in …Bibliography. "Amoeba" is a term that describes a simple eukaryotic organism that moves in a characteristic crawling fashion. However, a comparison of the genetic content of the various amoebas ...Protists are a very large group of phylogenetically distinct eukaryotes that can be unicellular, multicellular, heterotrophic, autotrophic, or mixotrophic. The share many similarities with but are ...25 Apr 2013 ... There are over 100000 described living species of protists, and it is unclear how many undescribed species may exist. Since many protists ...In fact, many protist cells are multinucleated; in some species, the nuclei are different sizes and have distinct roles in protist cell function. Single protist cells range in size from less than a micrometer to three meters in length to hectares (a single hectare is nearly 2.5 acres in size). Protist cells may be enveloped by animal-like cell ...13 Sept 2023 ... Kingdom Protista – Characteristics, Classification, Importance, Examples ... Kingdom Protista is one of the five kingdoms that classify various ...The protist then transports its cytoplasm into the pseudopod, thereby moving the entire cell. This type of motion, called cytoplasmic streaming, is used by several diverse groups of protists as a means of locomotion or as a …Protista. The Protista is a large complex grouping of mostly unicellular eukaryotic organisms. They are morphologically diverse and can be found in most terrestrial, aquatic, and marine habitats as free-living forms and as parasites of other protists, of fungi, and of plants and animals.Physarum, large genus of true slime molds, accounting for about 20 percent of the species of the phylum Mycetozoa (Myxomycetes). Physarum polycephalum, a fast-growing species, is the most notable; it has been used widely in physiological experiments in protoplasmic streaming and nuclear behaviour. Physarum cinereum, which forms an ashy-gray ...Protists exhibit many forms of nutrition and may be aerobic or anaerobic. Those that store energy by photosynthesis belong to a group of photoautotrophs and are characterized by the presence of chloroplasts. Other protists are heterotrophic and consume organic materials (such as other organisms) to obtain nutrition. The protist then transports its cytoplasm into the pseudopod, thereby moving the entire cell. This type of motion, called cytoplasmic streaming, is used by several diverse groups of protists as a means of locomotion or as a method to distribute nutrients and oxygen. Figure 23.21 Ammonia tepida, a Rhizaria species viewed here using phase contrast light …Physarum, large genus of true slime molds, accounting for about 20 percent of the species of the phylum Mycetozoa (Myxomycetes). Physarum polycephalum, a fast-growing species, is the most notable; it has been used widely in physiological experiments in protoplasmic streaming and nuclear behaviour. Physarum cinereum, which forms an ashy-gray ...protist. Protists are mostly single-celled, microscopic organisms that are not considered to belong to the animal, plant, or fungi kingdoms. Instead, they are classified as members of the kingdom Protista. Protists are eukaryotes, which means that they have a true nucleus and organelles. Thousands of species of protists exist, and scientists ....