Answer
The endosymbiotic theory was put forward by Lynn Margulis in 1967. According to this theory: -
a. Mitochondria was formed by engulfing of aerobic bacteria (endocytosis) by a large anaerobic bacteria
b. Chloroplast was formed by engulfing of photosynthetic bacteria (endocytosis) by a large anaerobic bacteria
c. This relation was symbiotic (mutually beneficial for both).
The evidence for this theory is the fact that both mitochondria and chloroplast have DNA, RNA, ribosomes and chlorophyll which is similar to the bacterial DNA, RNA, ribosomes and chlorophyll of bacteria.
However, this theory failed to explain the double membranes of nuclear envelop of Mitochondria and Chloroplast.
Work Step by Step
As above
