The fact that chloroplasts the
organelles responsible for
in plants leads to
supposition that before symbiosis
were autotrophic prokaryotes. For
reason that mitochondria are center
of the aerobic respiration, the
powerhouse of eukaryotic cell, itis
supposed they were once aerobic
.

The endosymbiotic hypothesis to
the emergence of aerobic
autotrophic eukaryotic beings is
further by the following
: chloroplasts as well as
have their own DNA,
to bacterial DNA; chloroplasts
mitochondria reproduce asexually
by division, like bacteria do;
organelles have ribosomes and
proteins.