Question

Which of the following statements about the immune response are incorrect ? A. Neutrophils possess lobed nucleus.
B. Hormones are key mediators of an immune response.
C. Macrophages can be found in tissues throughout the body.
D. Eosinophils are the first cells to reach a site of infection.
E. The components of complement cascade are present in blood as inactive zymogens.
Choose the correct answer from the options given below :

• A. \(C \text{ and } D\) only
• B. \(B, C, D\) only
• C. \(B \text{ and } D\) only
• D. \(A, D, E\) only

Hint:

Remember:
• Neutrophils \(\rightarrow\) First responders in acute infection
• Eosinophils \(\rightarrow\) Allergy and parasite defense
• Complement proteins \(\rightarrow\) Inactive zymogens in blood Key immune mediators: \[ \text{Cytokines and chemokines} \]

Answer 1

The Correct Option is C

Concept: The immune response involves coordinated action of:
• Immune cells
• Cytokines
• Antibodies
• Complement proteins Different leukocytes perform specialized immune functions.

Step 1: Evaluating statement A. Statement A: \[ \text{Neutrophils possess lobed nucleus} \] This is correct. Neutrophils are polymorphonuclear leukocytes with: \[ 3-5 \text{ lobed nuclei} \] Thus: \[ \boxed{A \text{ is correct}} \]

Step 2: Evaluating statement B. Statement B: \[ \text{Hormones are key mediators of immune response} \] This is incorrect. The principal mediators of immune responses are:
• Cytokines
• Chemokines
• Antibodies Hormones may influence immunity but are not the key mediators. Thus: \[ \boxed{B \text{ is incorrect}} \]

Step 3: Evaluating statement C. Statement C: \[ \text{Macrophages are found throughout body tissues} \] This is correct. Examples include:
• Kupffer cells in liver
• Microglia in brain
• Alveolar macrophages in lungs Thus: \[ \boxed{C \text{ is correct}} \]

Step 4: Evaluating statement D. Statement D: \[ \text{Eosinophils are first cells to reach infection site} \] This is incorrect. The first leukocytes to reach sites of acute infection are: \[ \text{Neutrophils} \] Eosinophils are mainly associated with:
• Parasitic infections
• Allergic reactions Thus: \[ \boxed{D \text{ is incorrect}} \]

Step 5: Evaluating statement E. Statement E: \[ \text{Complement proteins exist as inactive zymogens} \] This is correct. Complement proteins circulate in inactive forms and become activated sequentially during complement activation. Thus: \[ \boxed{E \text{ is correct}} \] Therefore, the incorrect statements are: \[ \boxed{B \text{ and } D} \] Hence, the correct answer is: \[ \boxed{(C)\ B \text{ and } D \text{ only}} \]