Sagot :
Answer: the heart
Explanation: The heart is the key organ in the circulatory system. As a hollow, muscular pump, its main function is to propel blood throughout the body.
Answer:
Heart
it is important for us to study the levels of biological organization, to know where these organisms belong, in what environment they prosper or what are the characteristics that made these animals similar to each other.
Explanation:
The heart is one of the most complex and arguably the most vital organ contained within the human body. The heart is central to the circulatory system as it is the fist-sized pump that circulates the blood throughout the body.