BioIT Sem 1 08-09: Protists

Microscopic animals and their parts

1. Paramecium
a. Cytoplasmic streaming: moving cytoplasm around the edges of the animal
b. Contractile vacuole: located centrally; circular; tends to shrink and expand; there may be two of them
c. Nucleus: dark-colored central body; usually circular
d. Peristome: median location; the funnel-shaped opening that leads to the esophagus
e. Esophagus: constriction that leads from the peristome to the food vacuole
f. Food vacuole: end of the esophagus; dark-colored if it contains food

2. Rotifer (multicellular)
a. Corona: the anterior ring lined with ciliated cells
b. Eyespot: small dark-colored spot located immediately posterior to the corona
c. Stomach: large, central, dark-colored chamber (if it contains food)
d. Vitellarium: the outer transparent skin
e. Foot: the long posterior organ that serves for attachment
f. Toe: the end of the foot

3. Planaria (multicellular)
a. Ocelli: the two eyespots
b. Mouth: the opening of the gastrointestinal tract, located ventral and medial
c. Pharynx: passage from the mouth to the two lateral branches of the gastrointestinal tract

4. Hydra (multicellular)
a. Mouth: located at the base of the tentacles
b. Tentacles: arms
c. Ectoderm: the outer layer of the skin
d. Gastroderm: the lining of the digestive cavity
e. Digestive cavity: hollow cavity where digestion takes place
f. Mesoglea: layer of cells between the ectoderm and the gastroderm

5. Euglena
a. Flagellum: whip-like motor organelle located posteriorly
b. Nucleus: large, round, central, dark-colored body; distinguished from the smaller eyespot
c. Eyespot: small, red-colored photoreceptor located anteriorly
d. Chloroplasts: green-colored organelles generally distributed throughout the body

6. Vorticella
a. Three rows of cilia: motile organelles located anteriorly forming three rows
b. Buccal funnel: or mouth; at the base of the rows of cilia
c. Superficial pellicle: the outer covering of the animal
d. Vacuole: contractile organelle located inside the animal
e. Macronucleus: central, dark body containing DNA; in the form of a horse-shoe
f. Peduncle: coiled spring-like appendage that attaches the animal to the substrate

REPORT ON

1. Taxonomy, anatomy, habitat, and food requirements.

2. Significance to humans. Summarize a recent research article to illustrate. For example: Upadhyaya A et al. Power limited contraction dynamics of Vorticella convallaria: an ultrafast biological spring. Biophys J. 2008, 94(1):265-272. “Vorticella convallaria is one of the fastest and most powerful cellular machines. The cell body is attached to a substrate by a slender stalk containing a polymeric structure---the spasmoneme. Helical coiling of the stalk results from rapid contraction of the spasmoneme, an event mediated by calcium binding to a negatively charged polymeric backbone. We use high-speed imaging to measure the contraction velocity as a function of the viscosity of the external environment and find that the maximum velocity scales inversely with the square root of the velocity. This can be explained if the rate of contraction is ultimately limited by the power delivered by the actively contracting spasmoneme…etc.”. Explain this to us in layman’s terms, especially the significance to humans. You may use illustrations and other strategies to make the presentation good. Suggested sources: PUBMED (a search engine that will give mostly summaries); Scientific American.