Question

Which of the following is an example of passive immunity?

• A. Skin acting as a physical barrier to pathogens
• B. IgG Antibodies passed from mother to fetus through the placenta
• C. Immune response to a specific antigen after vaccination
• D. Production of interferons in response to a viral infection

Hint:

Passive = pre-formed antibodies (e.g. maternal IgG across placenta).

Answer 1

The Correct Option is B

Passive immunity involves the transfer of pre-formed antibodies, like IgG from mother to fetus via the placenta. It provides immediate, short-term immunity without activating the recipient’s immune system.