Chloroplast
Mitochondria also had a similar origin, but chloroplasts are found only in plants and protists. In green plants, chloroplasts are surrounded by two lipid-bilayer membranes. They may be the outer and inner membranes of the ancestral cyanobacterium. Chloroplasts have their own genome, much smaller than that of free-living cyanobacteria. The DNA which remains shows clear similarities with the cyanobacterial genome.