1. The Immune System

2. Which of the following in vertebrates has the same function as hemocytes in insects?
Toll-like receptor
interferon
complement system
neutrophils
mast cells
Answer: D

3. Which of the following in vertebrates has the same function as hemocytes in insects?
Toll-like receptor
interferon
complement system
neutrophils
mast cells

4. The specificity of a particular antibody for its target epitope is determined by
the variable regions.
the constant regions.
the light chains.
the heavy chains.
the transmembrane region.
Answer: A

5. The specificity of a particular antibody for its target epitope is determined by
the variable regions.
the constant regions.
the light chains.
the heavy chains.
the transmembrane region.

6. The exceptionally large diversity of antigen receptors found on B cells and T cells is mostly the result of
random mutations.
clonal selection.
alternate splicing.
recombinase activity.
gene duplication.
Answer: D 6

7. The exceptionally large diversity of antigen receptors found on B cells and T cells is mostly the result of
random mutations.
clonal selection.
alternate splicing.
recombinase activity.
gene duplication. 7

8. What is true of a secondary immune response?
It is brought about by memory cells.
It is less effective than a primary immune response.
It includes a humoral response but not a cell-mediated response.
After it occurs, the immune system can only respond to reinfection with the same antigen by mounting another primary immune response.
1 only d) 2, 3, and 4
1 and 2 e) 1, 2, and 3
1 and 3
Answer: A 8

9. What is true of a secondary immune response?
It is brought about by memory cells.
It is less effective than a primary immune response.
It includes a humoral response but not a cell-mediated response.
After it occurs, the immune system can only respond to reinfection with the same antigen by mounting another primary immune response.
1 only d) 2, 3, and 4
1 and 2 e) 1, 2, and 3
1 and 3 9

10. Consider this graph of the immune response to antigens A and B
Consider this graph of the immune response to antigens A and B. If you expose this individual to antigen C on day 56, what do you expect to see?
103 antibodies to B on day 61
104 antibodies to A on day 61
101 antibodies to C on day 61
101 antibodies to C on day 67
101 antibodies to A on day 67
Answer: D

11. Consider this graph of the immune response to antigens A and B
Consider this graph of the immune response to antigens A and B. If you expose this individual to antigen C on day 56, what do you expect to see?
103 antibodies to B on day 61
104 antibodies to A on day 61
101 antibodies to C on day 61
101 antibodies to C on day 67
101 antibodies to A on day 67

12. Which of the following is required to activate a cell-mediated or humoral immune response to a foreign molecule?
cytokines secreted by helper T cells
perforins secreted by cytotoxic T cells
granzymes secreted by cytotoxic T cells
antibodies secreted by plasma cells
complement proteins secreted by the liver
Answer: A 12

13. Which of the following is required to activate a cell-mediated or humoral immune response to a foreign molecule?
cytokines secreted by helper T cells
perforins secreted by cytotoxic T cells
granzymes secreted by cytotoxic T cells
antibodies secreted by plasma cells
complement proteins secreted by the liver 13

14. Which defensive chemical is improperly matched with a function?
perforins—lysis
antibodies—pathogen neutralization
histamines—dilate capillaries
cytokines—immune cell stimulation
lysozymes—cause fevers
Answer: E 14

15. Which defensive chemical is improperly matched with a function?
perforins—lysis
antibodies—pathogen neutralization
histamines—dilate capillaries
cytokines—immune cell stimulation
lysozymes—cause fevers 15

16. What is the correct sequence in which the following occur during a primary humoral immune response?
B cell activation
helper T cell activation
plasma cell differentiation and proliferation
antibody secretion
presentation of antigen on class II MHC proteins
5, 2, 1, 4, 3 d) 4, 5, 3, 1, 2
4, 5, 2, 1, 3 e) 5, 2, 1, 2, 3
5, 1, 2, 3, 4
Answer: E 16

17. What is the correct sequence in which the following occur during a primary humoral immune response?
B cell activation
helper T cell activation
plasma cell differentiation and proliferation
antibody secretion
presentation of antigen on class II MHC proteins
5, 2, 1, 4, 3 d) 4, 5, 3, 1, 2
4, 5, 2, 1, 3 e) 5, 2, 1, 2, 3
5, 1, 2, 3, 4 17

18. What is “matched” between donor tissue and recipient in order to increase likelihood of successful transplantation?
antigens
allergens
Toll-like receptors
MHC proteins
antibodies
Answer: D 18

19. What is “matched” between donor tissue and recipient in order to increase likelihood of successful transplantation?
antigens
allergens
Toll-like receptors
MHC proteins
antibodies 19

20. Which of the following is characteristic of herpesvirus infections?
increased antigenic variation
latency
direct attack on the immune system
causes liver cancer
is not affected by stress
Answer: B

21. Which of the following is characteristic of herpesvirus infections?
increased antigenic variation
latency
direct attack on the immune system
causes liver cancer
is not affected by stress

22. Scientific Skills Questions

23. The glycoproteins covering a trypanosome’s surface are encoded by a gene that is duplicated more than a thousand times in the organism’s genome. Each copy is slightly different. The number of trypanosomes was measured in 100 patients during the first few weeks of infection. What is the independent variable in this experiment?
time
number of trypanosomes
volume of blood
number of patients
Answer: A

24. The glycoproteins covering a trypanosome’s surface are encoded by a gene that is duplicated more than a thousand times in the organism’s genome. Each copy is slightly different. The number of trypanosomes was measured in 100 patients during the first few weeks of infection. What is the independent variable in this experiment?
time
number of trypanosomes
volume of blood
number of patients

25. The glycoproteins covering a trypanosome’s surface are encoded by a gene that is duplicated more than a thousand times in the organism’s genome. Each copy is slightly different. The number of trypanosomes was measured in 100 patients during the first few weeks of infection. What is the dependent variable in this experiment?
time
number of trypanosomes
volume of blood
number of patients
Answer: B

26. The glycoproteins covering a trypanosome’s surface are encoded by a gene that is duplicated more than a thousand times in the organism’s genome. Each copy is slightly different. The number of trypanosomes was measured in 100 patients during the first few weeks of infection. What is the dependent variable in this experiment?
time
number of trypanosomes
volume of blood
number of patients

27. Assume that a decrease in trypanosome abundance indicates an effective immune response. What is the best explanation for the experimental results shown in this graph?
By the time the host developed an immune response to one glycoprotein, the parasite had changed to a different glycoprotein.
The host was infected by new parasites three times during the course of the study.
The immune response went through cycles of strength and weakness.
The parasite went through regular cycles of reproduction followed by death.
Answer: A

28. Assume that a decrease in trypanosome abundance indicates an effective immune response. What is the best explanation for the experimental results shown in this graph?
By the time the host developed an immune response to one glycoprotein, the parasite had changed to a different glycoprotein.
The host was infected by new parasites three times during the course of the study.
The immune response went through cycles of strength and weakness.
The parasite went through regular cycles of reproduction followed by death.

29. Later, antibodies specific for different glycoproteins were discovered
Later, antibodies specific for different glycoproteins were discovered. Does the data in this graph support the hypothesis that the parasite switched surface glycoproteins once the host immune system responded to the original glycoprotein?
Yes. The data suggest that the parasite first displayed glycoprotein B, then glycoprotein A, and then a third glycoprotein.
Yes. The data suggest that the parasite first displayed glycoprotein A, then glycoprotein B, and then a third glycoprotein.
No. The data suggest that the parasite consistently displayed glycoprotein B.
No. The data suggest that the parasite consistently displayed glycoprotein A.
Answer: B

30. Later, antibodies specific for different glycoproteins were discovered
Later, antibodies specific for different glycoproteins were discovered. Does the data in this graph support the hypothesis that the parasite switched surface glycoproteins once the host immune system responded to the original glycoprotein?
Yes. The data suggest that the parasite first displayed glycoprotein B, then glycoprotein A, and then a third glycoprotein.
Yes. The data suggest that the parasite first displayed glycoprotein A, then glycoprotein B, and then a third glycoprotein.
No. The data suggest that the parasite consistently displayed glycoprotein B.
No. The data suggest that the parasite consistently displayed glycoprotein A.