Answer:
The three-chambered hearts of amphibians and nonbird reptiles are facultative, allowing variation in blood flow through the heart.
Explanation:
In Anatomy, cardiac cycle can be defined as a complete heartbeat of the human heart which comprises of sequential alternating contraction and relaxation of the atria and ventricles, therefore causing blood to flow unidirectionally (one direction) throughout the human body.
Generally, the cardiac cycle occurs in two (2) stages;
I. Diastole : in this stage, the ventricles is relaxed and would be filled with blood.
II. Systole: at this stage, the muscles contracts and thus, allow blood to be pushed through the atria.
All amphibians and reptiles except for crocodiles (having four-chambered heart) have three-chambered hearts, which typically comprises of a partially divided ventricle and two atria.
Hence, the correct statement about the three-chambered hearts of amphibians and nonbird reptiles is that, the three-chambered hearts of amphibians and nonbird reptiles are facultative, allowing variation in blood flow through the heart due to the partially divided ventricle.
Answer:
To build. This building will help people and bring high quality
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Answer:
Plants are valuable since they provide our food, materials for shelter, and purify the air (photosynthesis).
Animals such like livestock, supply us with food, fiber and leather.
The Endangered species act can help a local economy because it helps to supply clean air and pure water. It also protects our natural supplies.
Isolate the cytoplasm from the external environmentRegulate the exchange of substancesCommunicate with other cellsIdentificationHope this helps :P
The answer to this question would be true.