Sustaining Life: Maintaining Chloroplasts and Mitochondria and their ... Chloroplast and Mitochondrial Division. As chloroplasts and mitochondria do not derive de novo they need to divide by fission to be maintained and increase populations in leaf development. Chloroplast division [] (Figure 1 a) is reasonably well understood [6,7].Chloroplasts are the most important members of the plastid family and are derived from proplastids present in the leaf primordia [8,9].