Answer:
Cell
Explanation:
A cell is the smallest unit of a living thing.
Cyanobacteria were very simple organisms and performed were an role in changing Earth's early atmosphere. They carried out photosynthesis to produce the materials they needed to grow. In this process, they release Oxygen which is needed to sustain life on Earth for Humans and other organisms.
B. They are determined by I, AB, A, or B
Scientists<span> are people who use research and experiments to learn more about the natural world. </span>Scientists<span> use scientific methods to derive knowledge systematically, performing repeatable experiments to ensure that their conclusions are valid and accurate.</span>