Protist

• These are simple eukaryotic organisms that live in water, damp terrestrial environments or even as parasites.


  Protists
• this is the outer membrane or skin of protists

  pellicle
• What Greek word was "protista" derived from?

  protistos
• protistos means?

  the very first
• Protists are traditionally considered the first eukaryotic forms of life and a predecessor to plants, animals and fungi.
• What is the primary feature of all protists?

  eukaryotic organisms
• Protists are usually aquatic, present in the soil or in areas with moisture.
• Most protists are unicellular organisms, but some are multicellular such as kelp.
• Protists have a nucleus and membrane-bound organelles.
• Protists are autotrophic (produce their own food), heterotrophic (feed on other organisms), and decomposers (feed on decaying matters).
• Symbiosis is observed in protists, where in one organism benefit at the expense of others.
• Parasitism is also observed in protists. For example, Trypanosoma protozoa is a parasite that causes sleeping sickness.
• Protists exhibit locomotion through cilia and flagella.
• What is pseudopodia?

  false feet
• How do protists reproduce?

  asexual reproduction
• Classification of protista

  protozoa, slime moulds, chrysophytes, dinoflagellates, euglenoids
• Protozoans are unicellular organisms.
• Protozoans were also called “animal” protists as they are heterotrophic and showed animal-like behaviours.
• This is a protozoa that can change its own shape indefinitely.

  amoeba
• A protozoa that has a definite slipper-like shape.


  paramecium
• A free-living protozoan that has chlorophyll, which means it can make its own food.

  euglena
• 4 major groups of protozoans

  amoeboid protozoans, flagellated protozoans, ciliated protozoans, sporozoans
• Protozoans mostly found in water bodies, either fresh or saline. They also have pseudopodia which help change their shape and capture and engulf food.


  amoeboid
• Protozoans that have flagella.

  flagellated
• They have cilia all over their body which help in locomotion as well as nutrition.


  ciliated
• These organisms are so-called because their life cycle has a spore-like stage. 


  sporozoans
• amoeboid example

  amoeba
• flagellated example

  euglena
• ciliated example

  paramecium
• sporozoans example

  plasmodium
• Slime moulds are saprophytic organisms (they feed on dead and decaying matter).
• Slime moulds are characterized by the presence of plasmodium.
• Chrysophytes, Dinoflagellates and Euglenoids are all unicellular organisms and photosynthetic. They are characterized by a stiff cell wall.
• Example of chrysophytes include diatoms and golden algae.
• Dinoflagellates are photosynthetic and found in various different colours, according to the pigment present in them. They show bioluminescence and known to cause red tide.
• The outer body covering is a protein-rich layer known as a pellicle.