The main thing that Stanley Miller's experiment in 1953 illustrated regarding the origins of life was that "<span>a. It produced the chemicals of life by simulating earth's early conditions" since he shot a beam of light through different chemicals. </span>
Answer:
B) The "lub-dub" sound originates from blood turbulence through the heart.
Explanation:
The systole and diastole in the heart produce the lub and dub sound in the heart.
The systole represents the contraction of both left and right ventricles and pumps the blood to the body and the right ventricle to the lungs. This involves the opening and closing of the valves. The closing of the atrioventricular valves produces lub sound.
At the end of the systole or ventricular contraction or when the blood has been pumped to the aorta and the pulmonary valves then the semilunar valves present in the aorta and pulmonary closes. This produces a sound dub.
Therefore,lub dub is associated with the physical contraction of the heart but not the turbulence of the blood.
Thus, the selected option is the correct answer.
Answer:
see below :)
Explanation:
There are three types of ecosystems; freshwater, ocean, and terrestrial.
The answer is D. Hope it helped. :)
