OpenStax Biology 2e Instructor Answer Guide
Biology 2e
Unit 7: Animal Structure and Function
Chapter 42: The Immune System
Visual Connection Questions
1. Which of the following statements about T cells is false?
c. MHC II is a receptor found on most body cells, while MHC I is a receptor found on immune
cells only
2. Based on what you know about MHC receptors, why do you think an organ transplanted
from an incompatible donor to a recipient will be rejected?
MHC receptors differ from person to person. Thus, MHC receptors on an incompatible donor
are considered “non-self” and are rejected by the immune system.
, OpenStax Biology 2e Instructor Answer Guide
3. The Rh antigen is found on Rh-positive red blood cells. An Rh-negative female can usually
carry an Rh-positive fetus to term without difficulty. However, if she has a second Rh-positive
fetus, her body may launch an immune attack that causes hemolytic disease of the newborn.
Why do you think hemolytic disease is only a problem during the second or subsequent
pregnancies?
If the blood of the mother and fetus mixes, memory cells that recognize the Rh antigen can
form late in the first pregnancy. During subsequent pregnancies, these memory cells launch an
immune attack on the fetal blood cells. Injection of anti-Rh antibody during the first pregnancy
prevents the immune response from occurring.
Review Questions
4. Which of the following is a barrier against pathogens provided by the skin?
d. desiccation
5. Although interferons have several effects, they are particularly useful against infections with
which type of pathogen?
b. viruses
6. Which organelle do phagocytes use to digest engulfed particles?
a. lysosome
7. Which innate immune system component uses MHC I molecules directly in its defense
strategy?
c. NK cells
Biology 2e
Unit 7: Animal Structure and Function
Chapter 42: The Immune System
Visual Connection Questions
1. Which of the following statements about T cells is false?
c. MHC II is a receptor found on most body cells, while MHC I is a receptor found on immune
cells only
2. Based on what you know about MHC receptors, why do you think an organ transplanted
from an incompatible donor to a recipient will be rejected?
MHC receptors differ from person to person. Thus, MHC receptors on an incompatible donor
are considered “non-self” and are rejected by the immune system.
, OpenStax Biology 2e Instructor Answer Guide
3. The Rh antigen is found on Rh-positive red blood cells. An Rh-negative female can usually
carry an Rh-positive fetus to term without difficulty. However, if she has a second Rh-positive
fetus, her body may launch an immune attack that causes hemolytic disease of the newborn.
Why do you think hemolytic disease is only a problem during the second or subsequent
pregnancies?
If the blood of the mother and fetus mixes, memory cells that recognize the Rh antigen can
form late in the first pregnancy. During subsequent pregnancies, these memory cells launch an
immune attack on the fetal blood cells. Injection of anti-Rh antibody during the first pregnancy
prevents the immune response from occurring.
Review Questions
4. Which of the following is a barrier against pathogens provided by the skin?
d. desiccation
5. Although interferons have several effects, they are particularly useful against infections with
which type of pathogen?
b. viruses
6. Which organelle do phagocytes use to digest engulfed particles?
a. lysosome
7. Which innate immune system component uses MHC I molecules directly in its defense
strategy?
c. NK cells
