True about sickle anemia is?

Ans. is 'b' i.e., Decreased ESR Investigation1) Peripheral smear shows sickle cells, target cells and Howell - Jolly bodies.2) ESR is decreased (only important anemia in which ESR is decreased, in most of other anemias ESR is increased).3) There is positive sickling test with a reducing substance like sodium metabisulfite.4) Hb electrophoresis shows two bands in heterozygous state/sickle cell trait (40% HbS & 60% HbA) and one bands in homozygous state (only HbS). HbS is slower moving than HbA towards positive electrode.5) Bone changes on X-ray showA. Fish mouth vertebraeB. Crew hair cut (hair on end) appearance of skull.(Hair on end appearance' is also seen in thalassemia, hereditary spherocytosis and G6PD deficiency.)6)There may be cardiomegaly and leukocytosis.7) Gamma Gandy bodies (nodules of hemosiderine and calcium deposition in spleen) are found.