AP BIO FR Ch. 43

Question 1

3 types of nonspecific defenses

Answer 1

1. Skin acts as a barrier against pathogens
2. Mucous membranes trap pathogens
3. Elimination through bodily fluids (sneezing, coughing, urination)

Question 2

How the immune system responds to initial pathogenic exposure and how it leads to quicker response second time around

Answer 2

Macrophages present the antigen. Helper T cells then activate B cells. B cells secrete antibodies that react against antigens. Cytotoxic T cells can cause apoptosis. Cytokines are secreted to signal or activate destruction of the antigens. Memory cells that are produced in primary response help speed up secondary responses.

Question 3

1 consequence of loss of B cell activity on initial and second exposures and a characteristic of immune response to bacterial pathogen not affected by loss of B cells

Answer 3

1. No antibodies produced
2. There second response is not faster than the first response.
3. Cell-mediated immunity is still active.