D the expansion of their territory
Answer:
Cyanobacteria
Explanation:
Cyanobacteria were the first photosynthetic autotrophs that used water molecules as the source of electrons. Cyanobacteria were the first autotrophs that performed oxygenic photosynthesis and carried out the splitting of water.
The process of splitting water released oxygen as a gas (O2) which was released in the atmosphere of the earth as a by-product. This led to the accumulation of oxygen in the atmosphere. Some cyanobacteria can fix nitrogen and have specialized cells called heterocyst which serve as the site for nitrogen fixation.
<span>the answer is light microscopes.</span>
It is thought that life arose on earth around four billion years ago. The endosymbiotic theory states that some of the organelles in today's eukaryotic cells were once prokaryotic microbes.
