Answer:
The percentage of carbon dioxide in the air is 0.04%
The answer is D, metaphase
The circle of life best illustrates natural selection
The cardiac muscle has intercalated disk that allows rapid transmission of the impulse. This will allow the cardiac muscle to have a coordinated way. The heart muscle has pacemaker that will spread the signal in regular time. The transmission of impulse is also controlled by a few checkpoint like the bundle of his to make the signal to the Purkinje fiber of left and right ventricle at the same time.