Question

bone marrow (stem cell) transplants have been used for the treatment and cure of a variety of cancers, immune system diseases, and blood diseases for many years.... in a person with sickle cell disease, the bone marrow produces red blood cells that contain hemoglobin s. this leads to the complications of sickle cell disease. to prepare for a bone marrow (stem cell) transplant, strong medicines, called chemotherapy, are used to weaken or destroy the patients own bone marrow, stem cells, and infection - fighting system. this is done so the patient does not reject the new blood cells coming from the donor. the patients bone marrow then is replaced with blood - forming stem cells from a donor who does not have sickle cell disease.... the actual transplant is given like a blood transfusion through an iv tube. the new bone marrow then produces red blood cells that are healthy since they do not contain a lot of hemoglobin s.

• \bone marrow (stem cell) transplant for sickle cell

how does a bone marrow transplant treat sickle cell disease?
bone marrow transplants produce healthy red blood cells containing hemoglobin s.
bone marrow transplants weaken the patients unhealthy bone marrow.
bone marrow transplants use chemotherapy to destroy the patients own bone marrow.
bone marrow transplants allow the patient to begin producing healthy red blood cells.

Explanation:

The text explains that in sickle cell disease, the patient's bone marrow makes abnormal red blood cells. Chemotherapy weakens/destroys the patient's bone marrow. Then donor blood - forming stem cells (without sickle cell trait) are transplanted. These new cells produce healthy red blood cells.

• Option 1: Incorrect as new cells shouldn't have hemoglobin S.
• Option 2: Incorrect as the goal is to replace, not just weaken.
• Option 3: Incorrect as chemotherapy is a prep step, not the transplant itself.
• Option 4: Correct as the transplant allows production of healthy red blood cells.

Answer:

Bone marrow transplants allow the patient to begin producing healthy red blood cells.