The ability of the immune system to attack transplanted tissue from an unrelated donor is mysterious because T cells should not be able to bind to foreign _______.1 pointMHC I and II moleculesendogenous (cytosolic) antigensexogenous (phagocytized) antigensβ microglobulinslipids and glycolipids

To answer the question step by step, let's break down the information provided and analyze it:

1. Understanding the Immune System's Role:

   • The immune system can attack transplanted tissue from an unrelated donor.
   • This ability is described as "mysterious."

2. Role of T Cells:

   • T cells are a type of immune cell that plays a crucial role in recognizing and responding to foreign substances.
   • The question implies that T cells should not be able to bind to certain foreign molecules.

3. Identifying the Foreign Molecules:

   • The options provided are:
     • MHC I and II molecules
     • Endogenous (cytosolic) antigens
     • Exogenous (phagocytized) antigens
     • β microglobulins
     • Lipids and glycolipids

4. Analyzing Each Option:

   • MHC I and II molecules: These are major histocompatibility complex molecules that present antigens to T cells. T cells are specifically designed to recognize antigens presented by MHC molecules.
   • Endogenous (cytosolic) antigens: These are antigens from within the cell, typically presented by MHC I molecules.
   • Exogenous (phagocytized) antigens: These are antigens from outside the cell, typically presented by MHC II molecules.
   • β microglobulins: These are components of MHC I molecules.
   • Lipids and glycolipids: These are types of molecules that can be part of cell membranes but are not typically involved in the direct recognition by T cells.

5. Determining the Correct Answer:

   • T cells are designed to recognize antigens presented by MHC molecules. Therefore, the "mysterious" aspect must relate to something T cells should not normally bind to.
   • The correct answer should be something that T cells are not expected to bind to directly.

Given this analysis, the correct answer is:

MHC I and II molecules