Chapter 15.2, Problem 2MC

Summary Introduction

To determine:

The evidence that mitochondria and chloroplasts descended from simpler cells engulfed long ago.

Concept introduction:

Endosymbiont theory proposes that both mitochondria and chloroplasts were once free-living bacteria that were engulfed by ancient bacteria. The aerobic bacteria became mitochondria of the today’s eukaryotic cells while the photosynthetic cyanobacteria became chloroplasts of today’s plant cells.