KINGDOM PROTISTABiology 112

Kingdom Protista

• All are simple eukaryotes (cells with nuclei).• Protists are an unusual group of organisms

that were put together because they don't really seem to belong to any other Kingdom

• Mostly microscopic• Live in moist surroundings.• Most unicellular *(amoeba); multicellular

(seaweed/kelp)• Autotrophs, heterotrophs, or both.• Some can move - others cannot.

3 categories of Protists:

•Animal-like

•Plant-like

•Fungus - like

Animal-like Protists (Protozoans)

* Unicellular heterotrophs

* Four groups based on movement:

• pseudopods,

• cilia,

• flagella,

• non-motile sporozoans.

Protozoans with PseudopodsProtozoans with Pseudopods Ex: AmoebaEx: Amoeba

1. Phylum Sarcodine

• Pseudopods also called ‘False Feet’

• Cell membrane pulls in one direction & the cytoplasm folds into the bulge.

http://www.youtube.com/watch?v=7pR7TNzJ_pA

Protozoans with ciliaEx: Paramecium

2. Phylum – Ciliates

• Cilia - hairlike structures - help organisms move, get food and sense environment.

• Unicellular with 2 nuclei: one for everyday functions and one for reproduction

• http://www.youtube.com/watch?v=FbDQfZOuyyk&feature=PlayList&p=9F5D3FC918ABE2F5&playnext_from=PL&playnext=1&index=17

Ciliates, cont.• Oral groove lined with cilia - moves

H20 containing food into food vacuole at end of oral groove.

• Food vacuole breaks down food and sends through cell.

• Anal pore sends out waste.

Oral groove

Contractile

Vacuole

Food vacuole

food

vacuole anal pore

macronucleus

micronucleus

Protozoans with flagella3. Phylum zooflagelates

• Use long whiplike part called flagella to move. (one or two)

• These usually live inside other organisms

• Trichomonas vaginalis: Trichomonas vaginalis: an STIan STI

Non-Motile Protozoans

4. Phylum Sporozoa – parasites • Feed on cells & body fluids of host

Sporozoans like plasmodium (causes malaria) feeds off liver and blood cells

Plantlike Protists

• Better known as algae

• Autotrophs (photosynthesis)

• Size: unicellular to very large

• Contain different pigments so they come in different colors.

• Algae perform 55-75% of all photosynthesis on Earth so it provides most of the world’s oxygen!

•Ex: colonial Volvox

Fungus-like Protists

• Fungus-like protists are heterotrophs that absorb nutrients from dead or decaying organic matter (decomposers/saprobes)

• Ex: slimemold, watermolds

Fungus-like Protists, con’t

• Land-dwelling water molds cause a number of plant diseases, including mildews and blights.

• A water mold Phytophthora infestans was responsible for the Irish Potato Famine!

Parasitic Protists

Parasitic Protists

Parasite: an organism that lives off of a HOST organism (either on it or in it) and causes harm to the host.

Vector: an organism that carries parasite, and can transfer the parasite to another organism.

Parasite Vector Host

MALARIA

Protist – PlasmodiumVector – Female Anopheles Mosquito

• 4 species of protozoans that carry malaria but Plasmodium falciparum is especially deadly

Vector / Protist?

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Malaria• WHO: 300-500 million cases/year• 1.5-2.7 million deaths/year (more than AIDS)

• Symptoms: fever, headache, vomiting and other flu-like symptoms

• The protist lives inside the bloodstream eventually clogging capillaries and destroying blood cells, leading to death if untreated.http://www.youtube.com/watch?

v=JwsoK8O0lXE

African Sleeping Sickness

• Protist – Trypanosoma• Vector – Tse Tse Fly

African Sleeping Sickness

• Occurs mostly in sub-saharan Africa• Initial symptoms: fever, headaches,

pain in joints• Infects the CNS: causes confusion,

lack of coordination and uncontrolled sleepiness.

• Leads to death if left untreated.• http://www.youtube.com/watch#!

v=4aVUrGO97Zg&feature=channel

Giardiasis

• Protist - Giardia• Infects ~ 200 million people worldwide

• Transmission: contaminated water (outdoor streams, other untreated water sources); day-care environments (fecal-oral route)

• Takes up residence in the digestive tract.

• Symptoms: severe diarrhea and vomiting.

Giardia