I think the correct answer from the choices listed above is option A. Sickle cell disease is caused by a change in allele. It is a disorder of the blood caused by an inherited abnormal hemoglobin. Hope this answers the question. Have a nice day.
B. is a protective structure made of cellulose fibrils
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A main sequence star is bigger than a neutron star,because neutron stars are remnant degenerate matter from a collapsed star,they are completely made out of Neutrons and are extremely dense,and have a diameter of only a several Kilometers.M<span>ost of them have a mass of 1.35-2 Solar masses.</span>
Since the other answer got deleted, i'll just answer it for you.
a sinoatrial node is the main pacemaker that begins each heartbeat located in the junctions of superior vena cava and the right atrium. It signals from the node that spread through the atria and determines the heart rates.
A and D because cytokinesis is where a single eukaryotic cell divides into two daughter cells. Gametogenesis is the name given to the process where the cell undergoes meiosis.
