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.
The reproductive system is different from other body systems in that the reproductive system functions in the survival of a species while all other body systems function to ensure the survival of the individual.
I don't know, maybe because of the way we see animals. Not as our equal parts
Answer:
All plasmids we manufactured are free of animal-derived materials and can contain low levels of endotoxin (<100EU/mg, on request). This process is designed to meet our customers’ diverse downstream applications such as transfection, antibody preparation, vaccine, and gene-therapy research, etc.