how is sickle cell anemia linked to malaria?

Answer 1

Malaria is caused by plasmodium falciparum, a bacteria that can be found in mosquito saliva. As a result of being bitten by the mosquito, p. falciparum causes the individual's red blood cells to burst open, or "lyse". This is a problem for individuals in Africa, where p. falciparum is common. Africans have evolved to have their cells "sickle", or change to a crescent shape. Sickle cells do not lyse in the presence of plasmodium falciparum, but as you probably know, it creates other problems (so it's an evolutionary "trade off"). Sickle cells dont flow through capillaries well, and therefore they cause a log jam in the capillaries, effectively blocking off efficient blood flow to the organ they are supplying. This can cause those tissues to die in the area of blockage, something called an "infarct". In sickle cell patients, splenic infarcts are very common, for example, so their spleens often have to be removed. Hope this helps!!!!

Answer 2

Haemoglobin S is a genetic mutation which has persisted and become prevalent in areas where malaria is common. It is a natural defence for the population as a whole, even though some people, namely those who have inherited faulty genes from both parents (SS), up until quite recently, died from the disease. Those who inherit just one faulty gene (AS) have an inborn defence against malaria.
The mechanism is simple.
A cell with HbS in it, when subjected to oxidative stress, such as low oxygen levels, will sickle, that is, sort of shrivel up, and be recognised as damaged and then be removed by the bodies recycling system. Generally in the spleen.
A malarial parasite normally seeks to hide within the red cells to avoid being recognised by the body's immune system. By the time the red cell nutrients are used up and the cell destroyed, the parasite has matured and may have spread throughout the blood and/or liver.
When a parasite enters a red cell which has a lot of HbS in it, the oxygen is quickly used up within the cell, and it sickles, this means that it will be damaged, and recycled in the spleen, and the parasite will be destroyed by the body's immune system.

For a population, it is more beneficial to have the mutation and to have some people die when they have the SS disease, than it is to not have it and lose more people to malaria.

This is a simplified version, but the basics are correct.

Answer 3

Cells with hemoglogin S (the mutanted hemoglobin of sickle cell disease) tend to sickle when infected by the malaria parasite. The spleen pulls the sickled cells out of the circulation, destroying them and the parasites contained within.

Answer 4

Sickle cell trait partially protects people from the deadly consequences of malaria.

Answer 5

People who have one sickle cell anemia gene ( you need two have the disease) show a resistance to getting malaria.

Answer 6

i have no clue

Answer 7

I don't know.