Question

Agranulocytes responsible for the immune response of the body are:
(a) Basophils
(b) Neutrophils
(c) Eosinophils
(d) Lymphocytes

Answer 1

Hint: Agranulocytes and granulocytes are the two types of WBCs.Different types of WBCs show different types of staining properties. The shape of the nucleus also varies in different leukocytes. The lobed nucleus is found in granulocytes.

Complete step by step answer:
Agranulocytes responsible for immune responses of the body are lymphocytes. Leukocytes of the blood have two main categories of WBCs – granulocytes and agranulocytes. Bone marrow and thymus provide a suitable micro- environment for the development and maturation of t- lymphocytes. B- lymphocytes are an important component of the humoral immune response. Produced in the bone marrow, B cells migrate to the spleen and other secondary lymphoid tissues where they mature and develop. T cells are involved in cell- mediated immunity, whereas B cells are primarily responsible for humoral immunity and are related to antibody production.

Additional information:
I- Neutrophils
- These cells have a horseshoe- shaped nucleus during the early stage but are further developed into a lobed nucleus.
- These cells take both acidic and basic stains and look violet- pink.
- The main function is phagocytosis, the reaction of inflammation and febrile response
II- Eosinophils
- These cells stain positive for peroxidase.
- They have granules like histamine, lysosomal enzyme, and ECF-A.
- They appear bright pink.
- The main function of these cells is phagocytosis, role in an allergic reaction, role in immunity, role in parasitic infection, etc.
III- Basophils
- They are irregular in shape as the boundary is not clearly defined because of overcrowding with coarse granules of heparin, histamine, and %- HT.
- These cells have a function of phagocytosis, role in an allergic reaction, the release of heparin, role in preventing the spread of allergic and inflammatory processes.
IV- Monocytes
- These cells resemble metamyelocytes.
- Monocytes have an eccentric or central round or oval nucleus.
- Monocytes from bone marrow migrate to the spleen
So the correct answer is, ‘Lymphocytes.’

Note:
- Neutrophils are the most abundant cells of WBC.
- Basophils are the least abundant cells of WBC.
- Spleen is a large bean- shaped organ that consists of lymphocytes and phagocytes and is also a reservoir of erythrocytes. It acts as a filter for blood by trapping blood- borne microorganisms.