Question

question 11 (1 point)
what is the main purpose of vaccination?
to immediately kill pathogens
to treat existing infections
to stimulate the production of memory cells
to increase white blood cell count
question 12 (bonus) (1 point)
which part of the antibody determines its class (e.g., igg, iga, etc.)?
antigen - binding site
variable region
light chain
constant region of the heavy chain

Explanation:

• Question 11: Vaccination introduces antigens (like weakened or inactivated pathogens). The immune system responds by producing antibodies and memory cells. Memory cells "remember" the pathogen, so if the real pathogen enters later, a faster and stronger immune response occurs. It's not for immediate pathogen killing (that's more like some drugs), not for treating existing infections (vaccines are preventive), and not mainly to increase white - blood cell count (though immune activation may cause some changes, but the key is memory cell production).
• Question 12: Antibodies have a Y - shaped structure. The constant region of the heavy chain has a specific amino - acid sequence that determines the antibody class (e.g., IgG, IgA). The antigen - binding site and variable region are more about binding to specific antigens, and the light chain is not the determinant of the antibody class.

Answer:

• Question 11: To stimulate the production of memory cells
• Question 12: Constant region of the heavy chain