Question

Select the incorrect statement out of the following.

• A. Neutrophils constitute the majority of leucocytes
• B. Eosinophils resist infection.
• C. Basophils secrete histamine and serotonin.
• D. RBCs in mammals are enucleated and biconvex in shape.

Answer 1

The correct option is D RBCs in mammals are enucleated and biconvex in shape.

(A) Neutrophils are the most abundant white blood cell, consisting of $60-70\%$ of the leukocytes, they defend against bacterial or fungal infection. They are referred to as PMN leukocytes.

(B) Eosinophil compose about $2-4\%$ of WBC. The count fluctuates. It rises in response to allergies, parasitic infections, collagen diseases, and disease of the spleen and CNS. That is they resist infection.

(C) Basophils are chiefly responsible for allergic and antigen response by releasing the chemical histamine & serotonin also heparin.

(D) Red Blood cells lack a nucleus, but are biconcave in shape, not Biconvex

Hence the correct option is D.