Answer:
Antibodies help you immune system.
Answer:
The first heart sound (S1) represents closure of the atrioventricular (mitral and tricuspid) valves as the ventricular pressures exceed atrial pressures at the beginning of systole (point a). S1 is normally a single sound because mitral and tricuspid valve closure occurs almost simultaneously.
Explanation:
The difference between the two DNA sequences, is that there was a C added to the new sequence. This mutation is called insertion