A. Genesis as well as C. Traits that can both be passed on
Mutation. this happens when a cell copies its DNA to divide. its more common than you may think, a "typo" occurs every 100, 000 or so nucleotides, thats about 120, 000 "typos" every time a cell divides.
Gene flow is the phenomenon of transfer of gene from one species/population to others. According to Natural Selection, more suitable (which fits best with the environment) gene/allele make the characteristic of that individual. So, it increases the ability to survive and reproduction
Hope this helps!
The mitochondria. An organelle with a very curious history....
