Dna is replicated during the subphase of interphase of the cell cycle

It is during Mitosis that DNA is replicated during the Synthesis phase of Interphase, which is the day-to-day life cycle of the cell. Cells stay in interphase, which occurs before Mitosis, which is also referred to as M phase.

Eukaryotic cells are theorized to have evolved from prokaryotes called the endosymbiotic theory. this explains that the most primitive eukaryotic cell engulfed a prokaryotic cell (by the process of phagocytosis) that is capable of cellular respiration and another prokaryotic cell that is capable of photosynthesis. these prokaryotic cells eventually became organelles and these organelles are the mitochondria and the chloroplast