A 40 yrs old male had undergone splenectomy 20 years ago. Peripheral blood smear examination would show the presence of:

1. Dohle bodies.
2. Hypersegmented neutrophils.
3. Spherocytes.
4. Howell-Jolly bodies.

The primary defect which leads to sickle cell anemia is:

1. An abnormality inn porphyrin part of hemoglobin.
2. Replacement of glutamate by valine in beta chain of HbA.
3. A nonsense mutation in the beta chain of HbA.
4. Substitution of valine by glutamate in the alpha chain of HbA.

A couple with a family history of beta thalassemia major in a distant relative, has come for counselling. The husband has HbA2 of 4.8% and the wife has HbA2 of 2.3%. The risk of having a child with beta thalassemia major is:

1. 50%
2. 25%
3. 5%
4. 0%

The HLA clas III region genes are important elements in :

1. Transplant rejection phenomenon.
2. Governing susceptibility to autoimmune diseases.
3. Immune surveillance .
4. Antigen presentation and elimination.

MHC Class III genes encode:

a. Complement component C3
b. Tumor necrosis factor.
c. Interleukin 2.
d. Beta 2 microglobulin.

Memory T cells can be identified using the following marker:

a. CD 45 RA.
b. CD 45 RB
c. CD 45 RC
d. CD 45 RO