<span>Heat and gases contracted within a nebula.</span>
Answer:
Miscigenation between ethnicities
Explanation:
Sickle-cell anemia is caused by disturbances in hemoglobin, one of the blood components. This disease can lead to kidney, liver, heart and bone complications.
Sickle cell anemia is a genetic disease originating in Africa, so white Americans usually do not have the sickle-shaped hemoglobin (Hemoglobin "S") gene.
Due to the miscegenation between West African blacks and American whites, the probability of having the allele gene for sickle cell anemia is <u>reduced but not canceled</u>.
Interestingly, the countries with the highest incidence of sickle cell anemia are the countries where there are endemic cases of malaria, a disease that directly attacks hemoglobin in blood, but cannot settle in the "S" hemoglobin characteristic of sickle cell anemia.
The answer to your question is,
if the oxygen poor blood mixes back with oxygen rich blood, that means that oxygen poor blood is not going back to the lungs to swap CO2 (carbon dioxide) with O2 (oxygen), and this swapping is vital to tissue survival, since oxygen is what keeps your tissues, muscles, and organs alive. so if this blood mixed, ultimately your organs are not receiving enough oxygen and will become starved of it, this can kill you and lots of people every year get heart surgery because their atrium or ventricles in their heart rupture
-Mabel <3