What is at the heart of the scientific process?

The heart of the scientific method is based on skepticism, critical thinking and curiosity. 

Experimentation is at the heart of the scientific method. Any scientist begins with the observation of natural phenomena, hypothesizes what may account for such phenomena, tests the hypotheses by manipulating some aspect of nature that can be controlled, and measures the result against the state of affairs when no such manipulation is implemented. In this way, hypotheses that do not match nature's laws are falsified when the independent variables manipulated do not account for predictable results. The falsifiability of hypotheses is the hallmark of science. Without experimentation, there is no science. Once there is an experimental finding that seems to demonstrate some understanding of hownature works, the results are communicated so that others may confirm or deny  the reliability of the hypotheses now bolstered by evidence. This limits theprobability that experimental results occurred by chance or were the outcome of human error. Thus, another important feature of science is replication. Any method used in any field of science must be reproduced by independent observers in order to be useful

Cell division is important to single celled organisms because it allows the cells to reproduce. through cell division, cells make exact copies of themselves. when single celled organisms go through cell division, they make exact copies of themselves which is how they reproduce.

It makes up an community