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.
It has an alternating chemical phosphate and sugar backbone, making the ‘sides’ of the ladder.
Open-mindedness is needed for the emerging scientific ideas to be accepted (or : to not be rejected without consideration).
Additionally, open-mindedness as a attitude often leads to new scientific ideas emerging: it means that people are more comfortable to try out new things and to test new hypotheses.
I believe that it is because when you put the hand on ice it causes the hand too cool and prevents/slows the rate at which the nerves get damaged.
