Protista

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PROTISTA
GENERAL CHARACTERISTICS
* Eukaryotic
* Unicellular
* Microorganisms
* Asexual/sexual reproduction
* Flagella & Cilia with 9+2 microtubules

ORIGIN
* The term "protist" is derived from the Greek protiston, meaning the "first of all ones." * Individual protists tend to be quite small, either unicellular or an undifferentiated multicellular mass. At one point, "Protista" encompassed everything that wasn't an animal or plant, until the advent of cellular biology which noted fundamental differences between bacteria and the rest of life. * Now bacteria are a separate category from protists.

GROUPS
* Animal-like Protists
(Mastigophorans, Sarcodines, Sporozoa, Ciliates) * Fungus-like Protists
(Myxomycota, Acrasiomycota)
* Plant-like Protists
(Euglenophytes, Chrysophytes,Dinoflagellates)

ANIMAL-LIKE PROTISTS
Protists that are classified as animal-like are called protozoans and share some common traits with animals.  All animal-like protists are heterotrophs.  Likewise, all animal-like protists are able to move in their environment in order to find their food.  Unlike, animals, however, animal-like protists are all unicellular.

SUB-GROUPS:
* Mastigophorans - Protists with flagella; mitotic division * Sarcodines - Protists with pseudopods ; by binary fission (mitosis) * Sporozoa - Parasitic protists; do not move on their own * Ciliates - Protists with cilia; reproduces asexually (binary fission) or sexually (conjugation)

ECONOMIC IMPORTANCE OF PROTOZOANS
1.  Food
Protozoa provide food for insect larvae, crustaceans and worms, which are taken by large animals like fishes, lobsters, clams, and crabs, which are eaten by man. 2. Symbiotic Protozoa
Certain protozoa like Trichonympha and Colonymphya etc. live in the gut of termites which help in the digestion of cellulose. 3. Insect Control
Several...
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