Natural selection is a process in which organisms have certain genotypic traits that allow them to better adapt to their environment over some time. In natural selection, the genotypic traits help organisms to survive and reproduce. Those traits are also favored as they are preserved, multiplied and transmitted from generation to generation at the expense of less beneficial traits.
Eukaryotic cells do not have a nucleus. The nucleus is where DNA, your genetic material, is usually stored. Prokaryotic cells do not have a nucleus. The DNA just floats around the cell instead of staying in one designated area.
