What is the primary difference between the innate and adaptive immune responses?

a. The innate immune response does not distinguish between pathogens, while the adaptive immune response does.

b. Only the innate immune response is activated by antigens.

c. The adaptive immune response generates immunological memory and is more specific than the innate immune response.

d. The innate immune response does not kill cells; the adaptive immune response does.

The overall role of the inflammatory response is to

a. Contain and eliminate foreign cells and material at the site of infection.

b. Increase heat at the site of infection to activate enzymes used in the immune response.

c. Produce antibodies that bind to and eliminate invading cells.

d. Increase blood flow at the site of a wound to flush out invading pathogens.

What is the difference between an epitope and an antigen?

What is one of the differences between CD4⁺ and CD8⁺ T cells?

a. CD4⁺ cells are immature, and CD8⁺ cells are mature.

b. CD4⁺ cells are activated, and CD8⁺ cells are not.

c. CD4⁺ cells interact with class II MHC proteins, and CD8⁺ cells interact with class I MHC proteins.

d. CD4⁺ cells activate cell-mediated responses, and CD8⁺ cells activate humoral responses.

Explain how gene recombination leads to the production of vast numbers of different B-cell receptors.

What steps are required for most B cells to become fully activated and differentiate into plasma cells?

Why is clonal selection necessary for the adaptive immune response but not the innate immune response? Select True or False for each statement.

T/F The adaptive immune response uses receptors to recognize pathogens, and the innate immune response does not.

T/F There is more receptor diversity in the adaptive immune response than in the innate immune response.

T/F Cells in the innate immune response do not require activation, and those in the adaptive immune response do.

T/F Clonal selection is used for targeting pathogens, and the innate immune response is used only to stop blood flow from the wound.

What would a vaccine have to contain to protect a patient from chicken pox? Explain why we don't have vaccines for HIV.

Which of the following outcomes would be expected if somatic hypermutation did not occur?

a. The diversity of pattern-recognition receptors would be significantly lowered.

b. B and T lymphocytes would not be able to produce receptors that recognize antigens.

c. The adaptive immune response would not be activated by pathogens.

d. The secondary immune response to a repeat infection would produce the same antibodies as those made in the primary immune response.

Propose a hypothesis to explain how self-reactive B cells are identified and eliminated during maturation.

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In developed countries, an enormous change has occurred within the human body over the past century—the loss of parasitic worms. Due to improvements in sanitation, roundworms that have inhabited human intestines (such as the hookworm above) and challenged our immune system for millions of years are no longer a threat. Does the end of this long-term relationship come at a cost?

What is the hygiene hypothesis? What correlation does it attempt to explain?

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In developed countries, an enormous change has occurred within the human body over the past century—the loss of parasitic worms. Due to improvements in sanitation, roundworms that have inhabited human intestines (such as the hookworm above) and challenged our immune system for millions of years are no longer a threat. Does the end of this long-term relationship come at a cost?

Explain how the adaptive and innate immune responses work together to defend the human body against infection by parasitic worms.

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In developed countries, an enormous change has occurred within the human body over the past century—the loss of parasitic worms. Due to improvements in sanitation, roundworms that have inhabited human intestines (such as the hookworm above) and challenged our immune system for millions of years are no longer a threat. Does the end of this long-term relationship come at a cost?

Pattern-recognition receptors have been identified that recognize worm products. Explain how these receptors are used to activate the adaptive immune response most appropriate for worm infection.

<Image>

In developed countries, an enormous change has occurred within the human body over the past century—the loss of parasitic worms. Due to improvements in sanitation, roundworms that have inhabited human intestines (such as the hookworm above) and challenged our immune system for millions of years are no longer a threat. Does the end of this long-term relationship come at a cost?

Parasitic worms modulate their host's immune response by inducing the proliferation of regulatory T cells. What role do these cells play in the adaptive immune response? How could this effect on regulatory T cells be linked to the hygiene hypothesis?

<Image>

In developed countries, an enormous change has occurred within the human body over the past century—the loss of parasitic worms. Due to improvements in sanitation, roundworms that have inhabited human intestines (such as the hookworm above) and challenged our immune system for millions of years are no longer a threat. Does the end of this long-term relationship come at a cost?

The roundworm Heligmosomoides polygyrus is a natural intestinal parasite of mice, and it offers an excellent model of the immunology of worm infections in humans. Scientists evaluated the impact of parasitic roundworms on immune disorders using mice prone to developing type 1 diabetes mellitus. Five-week-old mice were infected with H. polygyrus (Hp). Two weeks later, half of the mice were cured of the infection (Rx). When the mice were 40 weeks old, scientists calculated the percentage of mice that developed diabetes in both groups: those exposed to roundworms and those in uninfected control groups (** means P<0.01). What two conclusions are supported by the results shown below?

<Image>

In developed countries, an enormous change has occurred within the human body over the past century—the loss of parasitic worms. Due to improvements in sanitation, roundworms that have inhabited human intestines (such as the hookworm above) and challenged our immune system for millions of years are no longer a threat. Does the end of this long-term relationship come at a cost?

There is a strong association between the prevalence of diabetes mellitus in parents and their children. If you were a physician, would you ask parents who have type 1 diabetes to intentionally infect their children with intestinal worms? What additional information would you need to make this decision?