Oxygen did not become a major part of the atmosphere until photosynthetic organisms evolved later in Earth's history.

Once the atmosphere cleared, photosynthetic organisms like ferns and other plants returned.

More simply, these are toxic chemicals synthesized by photosynthetic organisms.

And as photosynthetic organisms spread throughout the world, oxygen increasingly became a major component of the atmosphere.

I think most all photosynthetic organisms would be.

The algae are a large and diverse group of photosynthetic organisms.

W/m measurements are important in energy balance considerations for photosynthetic organisms.

Most algae are eukaryotic, photosynthetic organisms that live in a wet environment.

Fossils of what are thought to be filamentous photosynthetic organisms have been dated at 3.4 billion years old.

Researchers compared 135 genes from 65 different species of photosynthetic organisms.