Chloroplasts are serni-autonomous in a eucaryotic cell in the way that mitochondria are.

They too have DNA, replication enzymes, and small ribosomes, although it is not clear what proteins are coded by chloroplast DNA.

Like mitochondria, chloroplasts are not constructed de novo by the cell, but reproduce within the cell by dividing. They are topologically outside the cell by virtue of a surrounding outer membrane, and are suspected of having originated initially as symbiotic blue-green algae.