1. Protozoa
Animal like Protists

2. Evolutionary Perspective
Protozoan is a complete organism in which all life activities are carried on within a single membrane
First fossil evidence of cells containing membrane bound structures 1.5 billion years old
Archaea and Eubacteria contributed to the origin of protists
Endosymbiont hypothesis explains how this could have occurred
Six phylogenitic protist Super groups are recognized
All protist groups were present by the cambrian period

3. Life within a single cell
Maintaining Homeostasis with organelles
Pellicle- microtubules under the cell membrane, maintains shape but is flexible
Cytoplasm differentiated into two regions
Ectoplasm- clear and firm
Endoplasm- granular more fluid
Contractile Vacuoles- expel excess water
Nutrition
Cytopharnyx- ingests larger food (mouth)
Endocytosis- thru membrane forms food vacuole
Smaller nutrients enter by active transport across membrane
Egestion vacuole expels undigested wastes

5. Single Cell
Protozoa are so small they have high surface area to volume ratio which facilitates difusion
Gas exchange of oxygen and carbon dioxide occurs easily
Excretion of Nitrogenous wastes (ammonia) by diffusion thru the cell membrane

6. Reproduction Both sexual and Asexual reproduction occur
Binary Fission- simplest asexual, occurs by mitosis producing two nuclei which separate when cytoplasm divides. Two identical cells
Some organelles duplicate as well to ensure each new cell is complete
Budding- mitosis produces new nucleus which is passed into cytoplasm much smaller than parent
Multiple Fission- mitosis produces many new nuclei which are passed on to multiple daughter cells
Sexual reproduction- sexually mature individual is haploid, gametes produced by mitosis, meiosis follows union of gametes

7. Super Groups
Excavata-Have feeding groove, flagellum or had one, feed by flagella generated current
Giardia- Anaerobic metabolism, causes waterborn disease in U.S
Trichomonas- flagellated, causes sexually transmitted disease
Euglena- flagella, posses chlorophyll, photosynthetic, pigment shield allows them to orient towards the light
Trypanosoma- cause African sleeping sickness from bite of Tsetse fly, attack central nervous system, Death if not treated
Amebozoa- when feeding and moving they form temporary extensions called pseudopodia, some lack a test or cell wall others have a test of calcium carbonate or chitin
Tubulinea- live anywhere they can remain moist, free living forms form tests of cemented minerals, many are parasites of invertabrates, fish, and mammals
Acanthamoebida- aerobic inhabitants of soil and water, two types are parasites of humans, one attacks brain the other infects the eye
Entamoebida- use pseudopodia to capture food, lack mitochondria, cause dysentery in humans by ulceration and inflammation in lower intestinal tract, diarrhea contains blood and mucus

8. Giardia

9. Trichomonas

10. Euglena

11. Trypanosoma

12. Tubulinea

13. Acanthamoebida

14. Entamoebida

15. Super Groups
Rhizaria- related to amoeboid some have fine pseudopodia used for feeding
Foraminiferia- primarily marine, form test of calcium carbonate, resemble spiral shells from beach, abundant in fossil record, formed chalk cliffs of Dover, planktonic
Heliozoans- some naked some have test with holes for axopodia, planktonic
Radiolaria- Planktonic, marine and fresh, radial symmetry test of silica, very porous for axopodia
Chromalveolata- diverse group, autotrophic mixotrophic or heterotrophic, all have plastids
Dinoflagellates- one flagellum that wraps around a central groove, spins on it axis, second flagellum propels it, contain chlorophyll and xanthophyll (reddish), can become so numerous they cause red tide and produce toxins that kill fish, Red sea was probably named after this
Plasmodium- tropical, causes malaria, 100 million people contract it yearly, is a bigger problem with global warming, spread by mosquito
Cryptosporidium- causes chronic diarrhea, only known protozoan to resist chlorination
Toxoplasma- found in cats and birds, spread in cat feces, causes stillbirths and spontaneous abortions in humans, fetuses that survive show mental retardation or epilepsy, keep cats away from sand boxes, no raw meat.
Paramecium-cilia covered membrane, ciliated oral groove leads to food vacuole, sexual reproduction with micronuclei, many live in the gut of hoofed mammals and contribute to digestion