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:
Substitution
Explanation:
Mutations can simply be defined as change in the structure of a gene. Mutation can be of different types. These include, but not limited to:
- Insertion: This involves the insertion of extra base pairs into a DNA
- Deletion: Loss of DNA section
- Substitution: When a nucleotide base gets substituted with another base.
<em>Substitution of a base can lead to coding of different amino acid and hence, protein. It can also lead to coding of the same amino acid, otherwise known as silent mutation. Base substitution can also lead to the amino-acid-coding codon becoming a stop codon, leading to an incomplete protein.</em>
The correct answer is substitution.
Process which by plants and animals break down sugar and turn it into energy.
Purpose is it provides cells with the energy they need to function.
Either an echo or a reverberation.
