Answer:
no 1. A is the answer
Explanation:
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Answer:
Autorhythmicity of the heart
Explanation:
It is the study of the characteristics features of the cardiac muscle cells with the ability to initiate action potential at certain level without connection to any external stimulus which the heart beats constantly and rhythmically. Cardiac muscle cells controls the rate of contraction of heartbeats.
Parasitism; the tick benefits from the human, the host.
