Mitochondria and chloroplasts are known as "semi-autonomous cell organelle".



Reason - They can self duplicate as they have circular DNA, 70S ribosomes, mRNA, tRNA, rRNA (for protein synthesis), required for duplication.



Mitochondria and chloroplasts are also known as "bacterial endosymbionts".



Reasons -



1. ETS (mechanism from which ATP sythesis occurs) is present



2. Presence of own nucleic acids and 70S ribosomes



3. Membranes resemble with that of bacteria (presence of proteins called porins)