U2:L3 Protists

Protists are a diverse collection of organisms. While exceptions exist, they are primarily microscopic and unicellular, or made up of a single cell. The cells of protists are highly organized with a nucleus and specialized cellular machinery called organelles.At one time, simple organisms such as amoebas and single-celled algae were classified together in a single taxonomic category: the kingdom Protista. However, the emergence of better genetic information has since led to a clearer understanding of evolutionary relationships among different groups of protists, and this classification system was rendered defunct. Understanding protists and their evolutionary history continue to be a matter of scientific discovery and discussion. They live in moist environments and vary in the ways they move and obtain energy. Protists are organisms that are classified into the Kingdom Protista. Although there is a lot of variety within the protist kingdom, they do share some common characteristics:- Protists are usually single celled organisms with a nucleus.- They live in moist environments.- They vary in the ways they move and obtain energy. NutritionThe animal-like protists must get their food from other organisms. These are often called protozoans. They are able to move to get food. Some move by using pseudopods, or "false feet." Their cell membrane pushes outward in one place, and the cytoplasm flows forward into the bulge. They use pseudopods to move away from bright light or to trap food. They can extend pseudopods on either side and trap a food particle. The food is absorbed into the cell. Amoeba and sarcodines are examples of protists that move by pseudopods. 5 Some animal-like protists move by using cilia. Cilia are hair-like projections that move with a wave-like pattern. The cilia move like tiny oars to sweep food toward the organism or to move the organism through water. An example of these is the paramecium. Protists obtain their energy in several ways:- Animal-like protists are heterotrophs that ingest or absorb food after capturing or trapping it.- Plant-like protists are autotrophs that produce food through photosynthesis.- Fungus-like protists are heterotrophs that obtain their food by external digestion either as decomposers or as parasites- Some protists have both autotrophic and heterotrophic characteristics. Animal-like Protists Protists that ingest or absorb food after capturing or trapping it Plant-like Protists Protists that produce food through photosynthesis Fungus-like Protists Protists that obtain their food by external digestion either as decomposers or as parasites Protists have three main ways to move (locomotion):- Flagellum (flagella) - a long whip-like tail used to move and catch food. An example of a flagellated protist is the euglena.- Cilia - small hair-like projections on the surface (cell membrane) of the cell used to sweep food into mouth-like structures and beat them in rhythm to move. An example of a ciliated protist is a paramecium.- Pseudopod – (false foot) a finger-like projection of the cell membrane and cytoplasm used to catch food and movement. An example of a protist with pseudopod is the amoeba. Label the organelle used to move for each protist shown below. The options are: cilia, flagellum, pseudopod. Flagellum Flagellum Pseudopod Cilia Match each vocabulary word with the correct definition. Pseudopod A false foot used to catch food and move Cilia Small, hair-like structures used to obtain food and move Flagellum A long, whip-like tail used to move and obtain food