Domain Bacteria
Chloroplasts

The Cyanobacteria gave to our planet the Chloroplast, which allowed the evolution of all green plants.

The Chloroplast allows plants to make their own food.

It's actually a cyanobacterium living within the plant's cells.

Sometime over 1/2 billion years ago, cyanobacteria took up residence within certain eukaryote cells, making food for the host in return for a home.