Human Immunity and Blood

If they produced anti-A antibodies, it would destroy their own blood. However, they do normally produce anti-B antibodies since B type blood would be alien to them.

Karl Landsteiner discovered the ABO system in 1900 and 1901 while trying to understand why blood transfusions sometimes saved lives and at other times caused death.

All the above statements are correct.

Lymphocytes are a type of white blood cells, which are responsible for protecting our body against bacterial and viral infections. They make up fifteen to forty percent of the total white blood cells that circulate in the blood stream. The two main types of lymphocytes are T cells and B cells, and both help to fight off infection and play a role in stopping the growth of cancers.

Fibrinogen is one of the important plasma proteins, which plays an important role in blood coagulation where it is converted by thrombin to fibrin. This is achieved through processes in the coagulation cascade that activates the zymogen prothrombin to the serine protease thrombin, which is responsible for converting fibrinogen into fibrin.

Blood group O individuals do not have either A or B antigens on the surface of their RBCs. But their blood serum contains IgM anti-A and anti-B antibodies against the A and B blood group antigens. Therefore, an individual of blood group O can receive blood only from a group O individual, but can donate blood to individuals of any ABO blood group (i.e. A, B, O or AB). They are known as universal donors.

This condition is called polycythemia.

Basophils remain in blood for short duration, and later migrate to the tissues. Basophils liberate heparin, an anticoagulant substance, which produce allergic reactions. They also liberate small quantities of bradykinin and serotonin, which participate in inflammatory process.

It is the cancer of blood cells. The bone marrow starts to make a lot of abnormal WBC called leukemia cells, which grow faster than normal cells. Leukemia cells can crowd out the normal blood cells. This can lead to serious problems such as anaemia, bleeding and infections.

When we are exposed to a variety of harmful pathogens such as bacteria, viruses, fungi and parasites which can cause diseases, our body has a specific defence mechanism to protect our body from these pathogens. Leucocytes or white blood cells play a major role in body's defence mechanism. In leucocytes, neutrophils are considered the first line of defence against infection.

Erythrocyte sedimentation rate is the rate at which red blood cells settle down. It is the measure of supernatant plasma separated out at the end of 1 hr when a column of blood mixed with an anticoagulant is kept undisturbed. ESR is increased in pregnancy and during menstruation, and also in infections like tuberculosis, rheumatoid arthritis, malignancy and anemia. ESR decreases in polycythemia and sickle cell anemia.

AB blood group is formed when alleles I^A and I^B come together. Both alleles are equally dominant so they are equally expressed as AB group.

This is the correct answer. The cross can be depicted as follows: Parents : AB x O Genotype: I^A, I^B x ii Gametes: I^A, I^B x i Offsprings: I^Ai and  I^Bi

This condition is called as polycythemia.

The blood stored in blood banks is called citrated whole blood. It is protected from coagulation by acid citrate dextrose.