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.
Answer: They move during that time because of the fact that the earth move around one its axis around the sun.
Explanation:
Electricity because most cities use electricity. and a generator would be to loud in a city
A possible effect of an error during transcription is the wrong amino acid chain, will be produced.
Option D
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The "wrong amino acid chain", will be produced as a possible effect of an error during transcription. A mutated set of proteins will start getting produced. They will have different or faulty functioning. In some cases, they won't have any functions of their own.
To avoid the possibility of an error, the transcript goes through a process of proofreading which further eliminates the chances of a wrong protein being developed.
An eon is 1.05 billion years and an era is 350 million years
