I am going to say a but I don’t know
Answer:
Closed the first one
Explanation:
In amphibians, reptiles, birds, and mammals, blood flow is directed in two circuits: one through the lungs and back to the heart, which is called pulmonary circulation, and the other throughout the rest of the body and its organs including the brain (systemic circulation).
most mammals, have closed cardiovascular systems. The two main circulation pathways in invertebrates are the single and double circulation pathways.
Making kids or reproduction(sex)
A DNA is made up 4 nucleotides bases The four ntd bases are ADININE, THYMYNE...
Answer:
Blood leaves the heart through the pulmonic valve, into the pulmonary artery, and to the lungs. Blood leaves the heart through the aortic valve, into the aorta, and to the body. This pattern is repeated, causing blood to flow continuously to the heart, lungs, and body.
Explanation:
