Talk in general about plastids.

Several types found in plants, bounded by two membranes that enclose a stroma. seen by LM but ultrastructure is only seen by EM, in stroma there are several circular DNA molecules, ribosomes, tRNA and all enzymes that are associated with DNA, In addition to membrane bounded sacks that comprise the photosynthesis chain and light absorbing molecules (pigments), they proliferate by binary fission.