The cells of SA node acts as the heart's peacemaker which establishes the pace for cardiac activity.
Sinoatrial node is also called sinus node.
SA node is termed as a group of cells which are located in the wall of the right atrium of the heart. Cells have the ability to produce electrical impulse. It travels to the heart via electrical conduction system which causes it to contract.
It produces action potential and also sets the rhythm of the heart.
There are exchanges that happen continuously in our bodies. One exchange is the gas exchange, or respiratory, system. This is the system where carbon dioxide is released from the lungs into the air, and oxygen is taken into the lungs from the air. This exchange happens in the air sacs of the lungs called the alveoli.
The answer to your question is two DNA molecules. 2 both copies consist of one new chain and one old chain nucleotides. half of the chain is part of the original DNA molecule the other brand new molecule
