The brain grows the most rapidly during the first years of life

The brain grows the most rapidly during the first months and years of life. During first months and years rapid growth and refinement in axons, dendrites, and synapses occur, especially in the cortex. A child's brain undergoes an amazing period of development from birth to to three- producing more than a million neural connections each second. The development of the brain is influenced by many factors, including a child's relationships, experiences and environment.

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.