It helped him because you can breed certain traits you want in things to get the traits you want
Diseases that can affect the circulatory system include:
Atherosclerosis. Atherosclerosis is a hardening of the arteries. ...
Heart attack. ...
Mitral valve prolapse. ...
Mitral valve regurgitation. ...
Mitral stenosis. ...
Angina pectoris. ...
Arrhythmia and dysrhythmia. ...
Cardiac Ischemia.
Hey friend,
Yes that is true
I really hoped i helped you!!!
Not true, certain chemical transmitters stimulate certain receptors