Answer
This theory was put forward by Lynn Margulis in 1967. According to this theory:
a. Mitochondria was made by endocytosis of aerobic bacteria
b. Chloroplasts were produced as a result of endocytosis of photosynthetic bacteria
c. The above two events happened because bacteria were not able to survive otherwise
d. This became a mutual beneficial relationship
Work Step by Step
This theory was put forward by Lynn Margulis in 1967. According to this theory:
a. Mitochondria was made by endocytosis of aerobic bacteria
b. Chloroplasts were produced as a result of endocytosis of photosynthetic bacteria
c. The above two events happened because bacteria were not able to survive otherwise
d. This became a mutual beneficial relationship