Biology 9700 · AS & A Level · Antibodies and vaccination
Antibodies and vaccination — practice question
There is a worldwide shortage of blood for transfusions. In the laboratory, researchers can grow bone marrow stem cells to produce red blood cells that may be used as an artificial blood product.
Rather than taking them directly from bone marrow, the researchers obtain bone marrow stem cells that are present in very small amounts in blood.
• Antibodies specific to bone marrow stem cells are fixed to tiny magnetic beads.
• The beads are mixed into a blood sample.
• An electric field is then used to keep the beads stationary so that the bone marrow stem cells can be collected.
(a)[1]
The antibodies are fixed to the beads so that the sites used to bind specific molecules on the bone marrow stem cells remain exposed.
Name the term for the specific molecules on the bone marrow stem cells that bind to the antibody binding sites.
(b)[3]
Suggest and explain the advantages of using bone marrow stem cells taken from the blood sample to manufacture artificial red blood cells.
(c)[3]
One desirable feature of artificial blood products, such as artificial red blood cells, is that they should be cheap to produce.
Suggest other desirable features of artificial blood products.
Worked solution & mark scheme
This 7-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Non‑self antigens are present” …