What were the characteristic of mitocondria and chloroplast that caused scientists to hypothosize that they were originaly prokaryotic cells that were engulfed by early eukaryotic cells?

Answer 1

Following characteristics of mitochondria and chloroplast led Margulis (1983) and other scientists to hypothesized that mitochondria and chloroplast were Bacteria and Cyanobacteria that were engulfed by Amoeboid Eucaryotic cells and became symbiotic organelles.

1; Both mitochondria and chloroplast (M&C) are self replicating.

2; Both possess small circular DNA molecule similar to Plasmids.

3; Both possess an outer membrane similar to eukaryotic cell membrane.

4; Both possess an inner membrane simillar to prokaryotic cell membrane as it lacks sterols.

5; Both possess ribosome similar to prokaryotes and smaller than eukaryotic ribosomes.

6; Both produce their own m RNA and some proteins .

7; Both can produce their own ATP.

8; Both are semidependent on animal or plant cell.

this hypothesis is called Endosymbiont hypothesis,

Answer 2

Scientists hypothesize that mitochondria and chloroplasts were originally prokaryotic cells that were engulfed by early eukaryotic cells because they have their own circular DNA similar to bacteria, reproduce by binary fission like bacteria, and have double membranes like cells that engulf other cells. Additionally, both organelles have ribosomes that are similar in structure and size to prokaryotic ribosomes.