Answer: Isograft.
- A Isograft
- B Xenograft
- C Allograft
- D Homograft
Correct answer: A. Isograft
Explanation: An isograft is between genetically identical individuals (identical twins), so the immune system does not treat it as foreign.
An antibody is Y-shaped, with two identical antigen-binding sites at the tips of the variable regions - each shaped to recognise one specific antigen - while the constant (Fc) region at the base is recognised by immune cells to trigger further responses.
Concept context
Innate and adaptive immunity, B cells, T cells, antibodies, vaccines, and immune disorders. Critical for NEET.