C. Decreased death rate is the answer
The explanations of natural phenomena, and additional hypothesis most often come about as a result of a scientific theory.
Explanation:
Scientific theory is a general explanation of natural phenomena developed through extensive and reproducible observations, more general and reliable than a hypothesis.
Then Every scientific theory starts as a hypothesis. A scientific hypothesis is a solution for an unexplained occurrence that does not fit into a currently accepted scientific theory. It must be based on careful rational examination of the facts.
I believe the answer to your question would be the <span>cerebellum and possibly the cortex</span>
In unicellular organisms such as bacteria, mitosis helps in asexual reproduction as it produces an identical copy of the parent cell. ... In the case of multicellular organisms, mitosis helps in growth and repair by producing more number of identical cells.