Whereas
in mammals the heart, which has four chambers, two ventricles and two atria, delivers oxygenated blood to the organs by one channel while the other directs blood to the lungs for re-oxygenation, the reptiles have three-chambered hearts with two ventricles and only one atrium.
A. in mammals the heart, which has four chambers, two ventricles and two atria, delivers oxygenated blood to the organs by one channel while the other directs blood to the lungs for re-oxygenation, the reptiles have three-chambered hearts with
B. in mammals the heart has four chambers, two ventricles and two atria, and delivers oxygenated blood to the organs by one channel while directs blood to the lungs for re-oxygenation by another, the heart in reptiles has three chambers,
C. the mammalian heart, consisting of four chambers, two ventricles and two atria, delivers oxygenated blood to the organs by one channel, while the other directs blood to the lungs for re-oxygenation, the reptilian heart has three chambers,
D. the mammals have hearts consisting of four chambers, two ventricles and two atria, which deliver oxygenated blood to the organs by one channel, while direct blood to the lungs for re-oxygenation by another, the reptiles’ hearts have three chambers,
E. the mammals have hearts consisting of four chambers, two ventricles and two atria, delivering oxygenated blood to the organs by one channel, while directing blood to the lungs for re-oxygenation by another, the reptiles’ hearts have three-chambers,