Question

How might the environment affect whether a symbiosis is mutualistic or parasitic? Be sure to answer this question by describing a particular symbiosis covered in class. For example, think about Rhizobia and legumes. How might availability of NH3 affect this relationship? Do you expect the plant to have different physiological responses to Rhizobia in these conditions? What do you think they could/should be and why?  

Compare and contrast the process of colonization by symbionts in animals versus plants.

Why do genomes in endosymbionts tend to get smaller?

Answer 1

Mutualism is the association of two organism in which both are benefited but in Parasitic mode of association one organism is benefitted and another is harmed. If the two species or organism have lesser chances to harm and there is scaracity of nutrient for both and the organisms have ability to synthesize different types of nutrient then the combination will be mutualistic. Rhizobium is a bacterium which us present in mutualistic association with leguminous plants. Presence of amonia will strengthen the association as more nutrogen will available. Endosymbionts are generally smaller to fitt in the partner body.