0Mitochondria
(1) Definition: (Gk – mito = thread ; chondrion = granule) Mitochondria are semi autonomous having hollow sac like structures present in all eukaryotes except mature RBCs of mammals and sieve tubes of phloem.
(2) These are absent in all prokaryotes like bacteria and cyanobacteria.
(3) Mitochondria are also called chondriosome, chondrioplast, plasmosomes, plastosomes and plastochondriane.
Plastids
(1) Definition: Plastids are semiautonomous organelles having DNA, RNA, Ribosomes and double membrane envelope which store or synthesize various types of organic compounds as ATP and NADPH + H+ etc.
(2) These are largest cell organelles in plant cell.
(3) History: Haeckel (1865) discovered plastid, but the term was first time used by Schimper (1883).
