Life Span Research Paper

Words: 436
Pages: 2

The life span of every human can be divided into two periods: prenatal and postnatal. The prenatal period begins with fertilization of the egg and ends with delivery. The cells began to duplicate and growth begins. Cell numbers increase and start to form masses. They divide mitotically for the whole life span of the individual, and they divide in different tissues. They continue to form into organs and all of the different tissues of the body. Eventualy they develop into a human body form. Life has begun.
When born babies have reflexes that are involuntary movements or actions. Some movements are spontaneous, occurring as part of the baby's usual activity. Others are responses to certain actions. Reflexes help identify normal brain and nerve