The p53 gene is a recessive tumor suppressor gene which functions as a key regulator for the cell cycle. In the event when only one p53 allele is mutated then the function of the p53 gene will persist and apoptosis (programmed cell death) will proceed if there are significant gene mutations in the cell. If two p53 alleles are mutated then the cell will not receive the signal to apoptose even with significant mutations and cancer will develop.
The brain can not completly function on its on until you are walking
The three mechanisms which regulate the heart are endocrine, cardiovascular and Sinoatrial nodes.
The endocrine system consists of the glands and hormones of the human body. The cardiovascular system is the organ system which is responsible for the circulation of the blood around the body and the oxygenation of the body's tissues. The sinoatrial node (SA node) generates the electrical impulses and is considered the natural pacemaker of the heart.