What are chemoheterotrophs

Please answeres the following questions in full details:

a) What are chemoheterotrophs? and how do they obtainenergy? name and describe two otherways    microorganisms obtain energy? Why do you think so many different wasys of obtaning energyevolved?

b) What support the idea that prokaryotes were involvedin the evolution of eukaryotes by means of endosymbiosis.

"Is this question part of your assignment? We can help"