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What do protist cells need to survive?
Most protists are aquatic organisms. They need a moist environment to survive and are found in places where there is enough water for them, such as marshes, puddles, damp soil, lakes, and the ocean. Some protists are free-living organisms and others are symbionts, living inside or on other organisms, including humans.
What are the ways that protists can feed?
The major modes of nutrition among protists are autotrophy (involving plastids, photosynthesis, and the organism’s manufacture of its own nutrients from the milieu) and heterotrophy (the taking in of nutrients).
How does a protist cell move?
Most protists are motile and generate movement with cilia, flagella, or pseudopodia.
How do unicellular protists obtain nutrients from the environment?
Protist Nutrition Protists get food in one of three ways. They may ingest, absorb, or make their own organic molecules. Ingestive protists ingest, or engulf, bacteria and other small particles. They extend their cell wall and cell membrane around the food item, forming a food vacuole.
How do protists obtain their food?
Protists get food in one of three ways. They may ingest, absorb, or make their own organic molecules. Ingestive protists ingest, or engulf, bacteria and other small particles. They extend their cell wall and cell membrane around the food item, forming a food vacuole.
What are the general characteristics of protists?
Protists share only a few general characteristics. A key feature of all protists are their eukaryotic cells. Because protists are eukaryotes, their cell or cells have a nucleus and membrane bound organelles. The vast majority of protists are single-celled organisms. Some single-celled protists live in colonies with other cells of the same species.
Do protists need oxygen to live?
Although most protists require oxygen (obligate aerobes), there are some that may or must rely on anaerobic metabolism—for example, parasitic forms inhabiting sites without free oxygen and some bottom-dwelling (benthic) ciliates that live in the sulfide zone of certain marine and freshwater sediments.
How do protists absorb and digest food?
Ingestive protists ingest, or engulf, bacteria and other small particles. They extend their cell wall and cell membrane around the food item, forming a food vacuole. Then enzymesdigest the food in the vacuole. Absorptive protists absorb food molecules across their cell membranes. This occurs by diffusion.
Do protists reproduce sexually or asexually?
Many have both asexual and sexual reproduction. An example is a protist called Spirogyra, a type of algae, shown Figure below. It usually exists as haploid cells that reproduce by binary fission. In a stressful environment, such as one that is very dry, Spirogyra may produce tough spores that can withstand harsh conditions.