Protozoa Flashcards
give a few examples of disease caused by protozoa
malaria, sleeping sickness, toxoplasmolysis
how did eukaryotes evolve from prokaryotes?
- parts of plasma memb fold back into cell
- created nuclear env and other organelles
- small prokaryotic cells enveloped by larger prokaryotes—-became mitochondria and chloroplast
what is are chimeras?
having a mixture of characteristics as a result of two or more genetically diff tissue types
what type of organism are protozoa?
- chimeras
- eukaryotic
- unicellular
- polyphyletic (from several lines of descent)
- no cell wall (unlike fungi)
- motile (except apicomplexans like Plasmodium-malaria)
functions of contractile vacuole, kinetoplast, glycosome, acidocalcisome and reservosome?
- store nutrients
- store enzymes
- control cell water content
give examples of the diverse characteristics of some protozoa?
- chloroplasts
- flagella
O some are considered algae - two identical nuclei w/ no mitochondria
- many nuclei w/no mitochondria
- two forms of nucleus
what are the major classes of protozoa?
- cilia eg Paramecium
- flagella eg Trypanosoma
- pseudopodia eg amoabae
- Apicomplexa
what can pseudopods do in protozoa?
engulf food
how do Euglena “sense” the direction of light?
- eyespot casts a shadow on the paraxonemal body O Euglena can sense the direction of light
what are the non major classes of protozoa? what is the importance of them?
- diatoms, role in FORENSIC INV as specific diatoms are only found in certain water bodies. Also responsible for 20% of worlds C fixation
what are slime moulds?
what are they like at low and sufficient nutrition levels?
- have characteristics of fungi and amoeba
- eukaryotic
LOW nutrients- slug like colonies
SUFFICIENT nutrients- single amoeboid cells
in the history of eukaryotes, how old are protozoa?
were EARLIEST eukaryotes O many uncharacteristic traits of eukaryotes
Most protozoa are chemoheterotrophs. what is a chemoheterotroph?
obtain nutrients by breaking down complex organic compounds
Slime molds are phagocytic. What does the term “phagocytic” mean?
Obtains large nutrient particles by endocytosis (i.e. engulfing food)
Protozoa that cause gastroenteritis form cysts. Those that cause blood-borne diseases do not. Why?
Faecal / waterborne transmission: cells are protected outside of the host organism.
Blood-borne: parasites spread between hosts via insect vectors. They are not exposed to the external environment
