LIFE SCIENCE

Detailed explanation-1: -Scientists believe that mitochondria evolved from aerobic, or oxygen-consuming, prokaryotes.

Detailed explanation-2: -The hypothesis that eukaryotic cells evolved from a symbiotic association of prokaryotes-endosymbiosis-is particularly well supported by studies of mitochondria and chloroplasts, which are thought to have evolved from bacteria living in large cells.

Detailed explanation-3: -There are two major organelles in eukaryotic organisms that have resulted from endosymbiosis, mitochondria (common to most eukaryotes) and chloroplasts (found in plants and algae only), as well as a few less obvious examples.

Detailed explanation-4: -Mitochondria evolved from endosymbiotic purple non-sulphur bacteria (-proteobacteria; John & Whatley 1975, 1977; Andersson et al. 2003), but precisely how has been unclear.

Detailed explanation-5: -The endosymbiotic theory states that mitochondria and chlopoplasts in today’s eukaryotic cells were once separate prokaryotic microbes.