Heating of the Earth due to the Sun's rays causes convection currents of air upwards. The warm air moves upwards, while cool air from nearby regions fills in the lower areas.
<span>Heating of the Earth can cause warm water currents that flow from hot areas like near the equator and tropical areas, while cold water currents flow from the arctic and antarctic regions and the temperate regions. </span>
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.