What is an organism from which others have descended?

How did the research presented in the article affect scientists' understanding of the evolution of eukaryotes

Which of the following are false concerning microbes? a. microbes generate oxygen through photosynthesis.b. the primary role of microbes on the planet involves causing disease in animals and humans.c. microbes produce vitamins in the intestines.d. microbes play a role in breaking down waste and decomposing dead organisms.

Witch type of microscope is used to view very small cell components like proteins and dna?