What Form of Photosynthesis Evolved First on Earth

Question

What form of photosynthesis evolved first on Earth?
A) oxygenic
B) anoxygenic
C) autotrophic
D) heterotrophic

Accepted Answer

Anoxygenic photosynthesis is believed to have evolved first on Earth, as it does not require the use of oxygen and can be performed by simpler organisms such as bacteria. Oxygenic photosynthesis, which produces oxygen as a byproduct, is a more complex process that likely evolved later in Earth's history. Autotrophic and heterotrophic refer to the way organisms obtain energy, not the type of photosynthesis they use.