Question 1

In comparing the antigen-binding site of an antibody to the binding site of an enzyme, which statement is true?

Accepted Answer

Antibodies bind to antigens without altering their covalent structure, serving primarily as markers for immune response. Enzymes, on the other hand, catalyze reactions that change the covalent structure of their substrates to facilitate biological processes.

Question 2

Which feature is characteristic of the innate immune response?

Accepted Answer

The innate immune response is characterized by its rapid response to invaders that trigger toll-like receptors (TLR), which can recognize various pathogen-associated molecular patterns (PAMPs).

Answer: D
 One characteristic of the adaptive immune response, not the innate immune response, is the ability to react to self-antigens. The innate immune response is more focused on recognizing and responding to non-self antigens.

Answer: E
 The adaptive immune response, not the innate immune response, is capable of recognizing a previously encountered antigen and responding more powerfully upon subsequent exposures. This is due to the ability of memory B and T cells to quickly mount an immune response.

Question 3

A human genome has genes that code for approximately 20,000 structural proteins and enzymes.This is _______ the number of specific antibodies a human genome can potentially code for.

Accepted Answer

The human genome can potentially code for millions of different specific antibodies, which is much more than the 20,000 structural proteins and enzymes it can code for. Therefore, choice A, "much less than," is the best choice.

Question 4

A child is born with a genetic disorder that impairs her ability to produce B and T lymphocytes.With this diagnosis, the symptom would you most likely see would be

Accepted Answer

B and T lymphocytes are key players in the adaptive immune response. Their impaired production would result in the absence of an adaptive immune response.

Question 5

DNA rearrangements in the B cell

Accepted Answer

DNA rearrangements in B cells are crucial for the generation of antibody diversity. Each B cell produces a unique antibody due to these rearrangements, enabling the immune system to recognize a vast array of antigens.

Question 6

If a person is exposed to a virus, which event is part of the activation phase in that person's adaptive immune response to the virus?

Accepted Answer

During the activation phase of the adaptive immune response, T-helper cells recognize an antigen on an antigen-presenting cell and release cytokines. This leads to the activation and proliferation of B cells and T cells specific for the viral antigen. Option A refers to the phagocytosis of a virus-infected cell, which is part of the innate immune response. Option B refers to the process of antigen presentation, but it is not specifically part of the activation phase. Option C refers to the production of antibodies, which is a later stage in the adaptive immune response. Option D refers to the phagocytosis of the virus by phagocytes, also part of the innate immune response.

Question 7

Which is an innate defense that is your first line of defense against a disease-carrying tick?

Accepted Answer

Skin is the first line of defense against tick bites as it physically blocks the entry of the tick and any disease-causing pathogens it may be carrying.

Question 8

Collagen is a structural protein that is necessary for the integrity of many of your tissues and organs.When a Treg is activated by binding to an antigen-MHC complex presenting a portion of a collagen molecule, the activated Treg will

Accepted Answer

When a Treg is activated by binding to an antigen-MHC complex presenting a portion of a collagen molecule, it will block the activation of T-helper and cytotoxic T cells that bind the same antigen-MHC complex, thereby suppressing the immune response against collagen. This helps to prevent autoimmune reactions and maintain tissue homeostasis.

Question 9

If you scrape your knee falling on asphalt, of the events listed, which is the first in the sequence of inflammatory responses at the wound site?

Accepted Answer

Mast cells are the first responders to injury or infection and release histamine, which triggers the dilation and increased permeability of blood vessels. This allows immune cells, such as phagocytes, to move into the wound area and begin the process of removing any pathogens or debris. The complement system and interferons play roles in later stages of the inflammatory response.

Question 10

If a person with a cold sneezes, and small droplets carrying the cold virus enter your nose as you breathe in, which is the first defense that will help protect you against the virus?

Accepted Answer

Mucus is the first line of defense against the cold virus as it traps the virus and prevents it from entering the body. The other options are part of the immune response that occurs after the virus has entered the body.

Question 11

For an organ transplant to be successful, it is often necessary to give the patient a drug that suppresses the cellular immune system.A drug that _______ is likely to be the most effective at immunosuppression.

Accepted Answer

Suppressing T-helper cells is crucial for effective immunosuppression because these cells play a central role in the immune response by activating other immune cells, including B cells and cytotoxic T cells. Suppressing their activity reduces the overall immune response, which is necessary to prevent the rejection of the transplanted organ.

Question 12

Refer to the figure below.  You would find the receptor labeled "B" on a _______ cell

Accepted Answer

The answer of Refer to the figure below.  You...

Question 13

A child comes down with the chickenpox, caused by the varicella-zoster virus.Her mother takes care of the child, exposing herself to the virus, but does not come down with chickenpox herself.What is the most likely explanation for this?

Accepted Answer

The mother harbored memory cells against the virus, having had chickenpox when she was young. This means that her immune system was able to quickly recognize and eliminate the virus, preventing her from coming down with the disease again.

Question 14

If an individual has inappropriately low levels of activity of Tregs, it is likely that the individual will develop a(n) _______ disease.

Accepted Answer

The answer of If an individual has inappropriately low levels...

Question 15

When receiving a lung transplant, a patient is likely to be treated with a drug that suppresses the _______ immune response.Unfortunately, this makes the patient more susceptible to cancer and infections.

Accepted Answer

The answer of When receiving a lung transplant, a patient...

Question 16

A fruit fly has an immune system that most likely shares which feature with that of humans?

Accepted Answer

Fruit flies, like humans, have an innate immune system that includes cells capable of phagocytosis, similar to macrophages in humans, which engulf and destroy invading pathogens.

Question 17

Which statement about T-helper cells is true?

Accepted Answer

T-helper cells recognize protein fragments presented by MHC molecules on antigen-presenting cells, and then activate other immune cells such as B cells and cytotoxic T cells.

Question 18

If a person suffers from hay fever due to an allergy to grass pollen, that person can be treated to reduce the allergic response by injections of small amounts of the allergen, a process called _______.

Accepted Answer

The answer of If a person suffers from hay fever...

Question 19

Vaccination against measles can prevent the disease in people because the vaccine

Accepted Answer

The measles vaccine contains a weakened or inactive form of the virus, which stimulates the body's immune system to produce a primary immune response without causing the disease. This prepares the immune system to recognize and fight the virus if exposed in the future, providing immunity against measles.

Question 20

If a new vaccine against HIV is developed, it will be important to test its effectiveness by determining if it stimulates both the production of antibodies in a humoral response against HIV and the proliferation of a clone of _______ that can destroy HIV-infected cells.

Accepted Answer

The answer of If a new vaccine against HIV is...

Quiz 41: Immunology: Animal Defense Systems