Question

Which immunoglobulin is produced first during a primary immune response?

• A. IgG
• B. IgA
• C. IgM
• D. IgE

Hint:

Remember: \[ \boxed{ \begin{aligned} \text{Primary immune response} &\rightarrow \mathrm{IgM} \text{Secondary immune response} &\rightarrow \mathrm{IgG} \end{aligned} } \] Mnemonic: \[ \boxed{\textbf{M = Made first}} \]

Answer 1

The Correct Option is C

Step 1: Recall the primary immune response. During the first exposure to an antigen, naïve B lymphocytes are activated and initially produce \[ \boxed{\mathrm{IgM}.} \]

Step 2: Identify the correct immunoglobulin. After class switching, antibodies such as IgG, IgA or IgE may be produced depending on the immune response. Therefore, the first antibody produced during a primary immune response is \[ \boxed{\mathrm{IgM}.} \] Hence, \[ \boxed{(C)} \] is the correct answer.