Interactions among Organisms
1. Paramecium bursaria have living algae inside. The algal cells are of the genus Zoochlorella sp. and are the producer in this symbiosis. Obviously the cells that contain the algae are protozoa, in the kingdom Protista. The protozoan symbiont provides a home for the algae, moving these algae into areas that are sunny.
2. Lichens are a symbiosis in which the green cells, algal protists or cyanobacteria, the kingdom Monera, are the producer, supplying the energy for life for themselves and the fungal component of the lichen. The fungal hyphae are clear threads that form support for the algae, providing moisture, protection, and minerals.
"Reindeer moss" is fruticose lichen and the other specimen available in our lab is referred to as foliose lichen, found on the bark of trees.
LICHENS (not a division, but rather a symbiotic association of an alga and a fungus)
3. Azolla is a tropical water fern that grows in rice paddies throughout the world. Cyanobacteria, kingdom Monera, called Anabaena grow in association with the fern, and fix nitrogen, an important nutrient for all living cells. The cyanobacteria are filaments of cells that have special cells called heterocysts that look a little different and are the sites of nitrogen-fixation. The water fern provides shade for the cyanobacteria in the harsh tropical sun. Finally the whole water fern/cyanobacteria complex breaks down and fertilizes the rice.
4. Termites are the hosts of several different internal symbionts--(l) several species of protozoa and (2) some cork- screw-like Monerans. The protozoa are covered with flagella that undulate and move the protozoa through the gut contents. The termite provides the meal by eating the wood (mainly cellulose) which is then digested by the symbionts, because the symbionts have an enzyme (cellulose) which the termite does not produce for itself. The termites and their symbionts can use as nutrient the sugar molecules of the digested cellulose. Actually very few organisms produce the cellulose-digesting enzyme, and that is a good thing. Civilization would not exist as we know it-wooden structures would not last long and there would be no paper. It would all be digested.
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