HSS 4102 Lecture Notes - Lecture 4: Herbicide, Horizontal Transmission, Atrazine

• School: University of Ottawa
• Department: Health Sciences
• Course: HSS 4102
• Professor: Ron Saulnier

Document Summary

Symbionts organisms of a different species that lives in close association with the host (ex. 2 categories of symbionts: parasitism when one partner benefits at the expense of another. (ex. Ticks, tapeworms, some wasps" species: mutualism beneficial for both partners (ex. Commensalism beneficial to one partner but neither beneficial or harmful to the other partner. Endosymbiosis one cell lives inside another cell (ex. Holobiont encompasses the eukaryotic organism and its persistent population of symbionts (ex. Cows with bacteria; termites need enzymes to digest wood) Mutualism is the basis for life on earth: ex. Between plants and bacteria: between bacteria and clams, between algae and coral. Nitrogen fixing nodules: the rhizobium bacteria is responsible for transforming elemental chemicals from the soil or air into biologically useful molecules, n2 nh4, form bacteroids which secret nitrogenase and leghemoglobin (carries o2 to bacteroids) Tidal and coal ecosystems: a quadruple symbiosis. Nitrogen fixing bacteria (in sea grass roots)