Flexi Says: The first photosynthetic organisms were bacteria that lived in the water. So, where did plants come from? Evidence shows that plants evolved from freshwater green algae, a protist. The similarities between green algae and plants is one piece of evidence. They both have cellulose in their cell walls, and they share many of the same chemicals that give them color. After that, plants have evolved several adaptations to life on land, including embryo retention, a cuticle, stomata, and vascular tissue.
