[Campbell Biology P.1009] Based on Figure 43.13 and the surrounding text, which of the follow... | Practice Question

Based on Figure 43.13 and the surrounding text, which of the following statements accurately describes antigen presentation?

  • A: An MHC molecule can only display a single, specific antigen fragment throughout its lifetime.
  • B: Antigen presentation primarily functions to hide foreign substances from T cells.
  • C: A T cell receptor is highly specific, binding to a single antigen fragment.
  • D: The interaction between an MHC molecule, an antigen fragment, and a T cell receptor is crucial for an adaptive immune response.

Explanation

Options C and D are both directly supported by the text. The text states that "the antigen receptor of a T cell is specific for a single antigen fragment" supporting C . It also explicitly says: "This interaction of an MHC molecule, an antigen fragment, and an antigen receptor triggers an adaptive immune response" supporting D . Option A is incorrect because an MHC molecule can display many different antigen fragments. Option B is incorrect because antigen presentation serves to "advertise" foreign substances, not hide them, to initiate an immune response.