Why sa node called pacemaker of heart

The SA Node is located in the outer layer of the right atrium of the heart, near the superior vena cava. It is made up of a group of cells (myocytes) positioned on the wall of the right atrium, at the center of the heart and near the entrance of the superior vena cava. These cells contract at a rate of about 70-80 times per minute, which make up the natural heart beat.

It controls the heart rate by producing electrical impulses

It controls the heart rate by producing electrical impulses and later transmitting electrical signals through the heart muscle, creating the heart to contract and pump blood everywhere into the body. The heartbeat originates from the S.A. node and expands to the walls of auricles which contract.

the father in the first generation probably had the recessive colorblind trait in his x chromosome. if he and his wife both had the colorblind trait, even if she had 1 recessive and 1 dominant, then that trait would be passed on to their kids.

(since you didn't attach the family tree this is just an assumption)

the function of the protein macromolecule is to move things in and out of the cell and transport other molecules in the body. there are many functions of proteins. they are the basic building blocks of living things and are responsible for the growth and repair of body cells and tissues.

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