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Kingdom Protista. If you look at a drop of pond water under a microscope, all the "little creatures" you see swimming around are protists. What is a Protist?. All protists have a nucleus and are therefore eukaryotic . Are either plant-like, animal-like or fungus-like.
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If you look at a drop of pond water under a microscope, all the "little creatures" you see swimming around areprotists.
What is a Protist? • All protists have a nucleus and are thereforeeukaryotic. • Are either plant-like, animal-like or fungus-like.
Heterotrophs vs. Autotrophs • Animal-like and fungus-like protists and are heterotrophs. They are organisms that cannot make its own food • Plant-like protists are autotrophs – they contain chloroplasts and make their own food.
Animal Like Protists • Protozoansare animal-like protists(heterotrophs)grouped according to how they move. • The wordprotozoameans "little animal." They are so named because many species behave like tiny animals—specifically, they hunt and gather other microbes as food.
All protozoa digest their food in stomach-like compartments called vacuoles. As they chow down, they make and give off nitrogen, which is an element that plants and other higher creatures can use. • Protozoa can be classified into three general groups based on how they move: • Pseudopods • Flagellum • Cilia
Pseudopods • Pseudopods: or “false foot” • Cell membrane pushes in one direction & the cytoplasm flows into the bulge. This allows the protozoan to move, dragging the rest of the cell behind it engulfing food as they go
Amoebae • Aquatic – lives in ponds, ditches, or slowly moving streams. • Just visible to the naked eye • Unicellular • Obtain nutrition by feeding on other animals • have a thin cell membrane but no cell wall. • no definite shape
EXAMPLE OF HOW PSEUDOPODS MOVE FLOW PUSH DRAG
It can form 2 pseudopods to surround & trap food. Then form a food vacuole to break down food in the cytoplasm.
Flagellum • The smallest of the protozoa • Flagellates (FLAJ-uh-lits) use their flagella to move, whip-like projections poking out of their cells, providing a back and forth movement • Can have one or several long flagella • Unicelluar • Has characteristics of both plants and animals
Euglena (yoo-glee-nuh) • Move freely and feed on other organisms • Makes its own food and also obtains nutrients by feeding as well. • Has an eyespot (to see) • When an eyespot detects light it uses flagellum to move toward the light so that its chloroplast can carry out photosynthesis
Cilia • Generally the largest protozoa • Unicellular, slipper shaped • Cilia – hair-like structures - help organisms move, get food and sense environment
Paramecium • Feeds with the help of a structure called an oral groove – where food is drawn in by external and internal cilia to form a food vacuole • Will eat the other two types of protozoa as well as bacteria. • Anal pore sends out waste • Aquatic - common in ponds and slow moving streams
Plant-like protists • Algae are eukaryotic autotrophs. • They, along with other eukaryotic autotrophs, form the foundation of Earth’s food chains. • They produce much of Earth’s oxygen. • Found in ponds and ditches, and even in shallow rain puddles
Volvox • Unicellular protists that has chloroplasts that can carry out photosynthesis • Does not live alone • Forms groups called colonies • Two small flagella that are used to move them • Cells near the surface are specialized to move the entire colony through water • Food source – makes its nutrients.
A Volvox is a hollow boll composed of hundreds of flagellated cells in a single layer.
