Answer: D) Pulmonary and aortic valves.
Explanation
There are two main heartbeats from a healthy heart.
The first beat is called the S1 or the lub, and it occurs when the atrioventricular valves (comprising the mitral and tricuspid valves) close.
The second beat is called the S2 or the dub, and it occurs when the semilunar valves (comprising the aortic and pulmonary valves) close.
Listening for heart beats is an essential part of cardiac auscultation.
A. Citric acid cycle (Krebs cycle)
The answer is A because genetic means it comes from your genes/parents genes so you know it’s either A or B because they both state something about your parents passing it to you. But you know it can’t be B because chloroplasts are only in plants and A says chromosomes which are in humans and relate to genes so we know it must be A.
