Which type of immune response is the body's first line of defense against infections?

Explanation: Todirectly destroy pathogens and infected cells. Antibodies are Y-shaped proteins produced by B cells in response to a specific pathogen. They bind to the surface of the pathogen and mark it for destruction by other components of the immune system or directly neutralize the pathogen.

Incorrect choices:

b. While antibodies can attract white blood cells to the site of infection, their primary role is not to do so but rather to directly target and neutralize pathogens.

c. Antibodies do not produce hormones but are part of the humoral immune response, which involves the production of antibodies to fight off infections.

d. Antibodies do not play a role in maintaining body temperature during infections; instead, fever is a response triggered by the release of certain chemicals called pyrogens during infections.

Explanation: The secondary immune response is faster and more potent than the primary immune response due to the presence of memory B cells and memory T cells. These memory cells "remember" the specific antigen from a previous encounter, allowing for a quicker and more effective immune response upon re-exposure to the same antigen.

Incorrect choices:
a. The secondary immune response is faster and stronger compared to the primary immune response, not delayed and weaker.
b. The secondary immune response involves the activation of memory B cells and memory T cells, not naive B cells and T cells.
d. The primary immune response is characterized by the production of IgM antibodies initially, but during the secondary immune response, the production of IgG antibodies predominates, which are more effective in neutralizing antigens.