How Organelle Genomes Resemble Bacteria

Mitochondrial and chloroplast genomes still keep several traits from their bacterial ancestors. They also show changes that happened after these organelles evolved inside eukaryotic cells. Eukaryotic cells are cells with a nucleus, while prokaryotes are cells without one.

Like prokaryotic genomes...

Primitive predator cells internalized bacteria that later evolved into mitochondria, forming eukaryotic cells. Photosynthetic cyanobacteria also formed symbiotic relationships with some of these eukaryotic cells and eventually developed into the chloroplast.

The present-day mitochondrial and chloroplast genomes are the remnants of these a...