Question 1

For the first nine months after birth,Ronny Knowse had not experienced any problems with sickness.After that,however,he had many severe bacterial infections.The reason for the delayed onset of this problem was

Accepted Answer

Passive natural immunity is when antibodies are passed from the mother to the baby through the placenta during pregnancy. These antibodies provide temporary protection to the baby until their own immune system develops. Therefore, it is likely that Ronny Knowse had passive natural immunity during the first nine months, which protected him from bacterial infections. Once the antibodies from the mother were no longer present, Ronny would have become vulnerable to infections.

Question 2

Functions of lymph nodes include

Accepted Answer

Lymph nodes act as filters in the lymphatic system, removing microorganisms and foreign substances from lymph before it is returned to the bloodstream. They do not suppress the immune system or filter out fat molecules present in lymph. While lymph nodes do play a role in tissue fluid movement, their main function is to filter lymph.

Question 3

Why doesn't interferon prevent all cells from being infected with viruses?

Accepted Answer

Interferon is only released from cells that are already infected and it has no memory capability, meaning that it can only act on cells that are currently infected and cannot prevent future infections. Additionally, interferon is effective against some viruses but not all, as viruses can develop mechanisms to evade or counteract interferon.

Question 4

____________ involves B cells.

Accepted Answer

Antibody-mediated (adaptive) immunity involves B cells producing antibodies in response to a specific antigen. B cells are a key part of the humoral arm of the adaptive immune response.

Question 5

Lymphocytes that survive the maturation process:

Accepted Answer

Lymphocytes that survive the maturation process in the thymus or bone marrow are now capable of recognizing and reacting to foreign substances called antigens, which trigger an immune response. These mature lymphocytes then migrate to various lymphatic tissue throughout the body, including the medulla of lymph nodes, where they can respond to antigens encountered during an infection or vaccination. Therefore, both choices A and C are correct.

Question 6

Ronny Knowse,a two-year old boy,chronically develops severe bacterial infections,which must be treated with antibiotics.When infected with viral diseases,however,he recovers uneventfully.A possible explanation might be

Accepted Answer

Ronny's ability to recover from viral infections suggests that his cell-mediated immunity is functioning properly, as this is primarily responsible for fighting viral infections. However, his chronic bacterial infections indicate a problem with antibody-mediated immunity, which is crucial for fighting bacterial infections.

Question 7

Which of these is a direct effect of antibodies?

Accepted Answer

Antibodies directly bind to antigens and form antigen-antibody complexes. These complexes can then be recognized and bound by other components of the immune system, such as complement proteins or phagocytic cells, leading to the inactivation and removal of the antigen. Therefore, the direct effect of antibodies is to bind antigens and inactivate them by forming complexes. Option A is incorrect because macrophages do not phagocytize the antibody, but rather the antigen-antibody complex. Option C is incorrect because it is the Fc region, not the constant region, of the antibody that triggers mast cell degranulation. Option D is incorrect because the constant region of the antibody does not activate the complement system, but instead must first bind to an antigen in order to trigger complement activation.

Question 8

Which of these is NOT a function of the lymphatic system?

Accepted Answer

The production of red blood cells is not a function of the lymphatic system. This is a function of the hematopoietic system, which includes the bone marrow and spleen.

Question 9

___________ is effective against extracellular antigens such as bacteria.

Accepted Answer

Antibody-mediated (adaptive) immunity involves the production and release of antibodies that specifically bind to extracellular antigens such as bacteria, neutralizing or eliminating them from the body. Innate immunity and cell-mediated (adaptive) immunity are more effective against intracellular pathogens, such as viruses, and do not involve the production of antibodies. Therefore, B is the best choice as it specifically mentions extracellular antigens.

Question 10

When a B cell is exposed to an antigen for the first time,

Accepted Answer

When a B cell is exposed to an antigen for the first time, the primary immune response occurs, during which the B cell divides to form plasma cells that produce antibodies and memory B cells for long-term immunity. However, T helper cells are not formed from B cells.

Question 11

Areas of rapidly dividing lymphocytes in lymph nodules are called

Accepted Answer

Areas of rapidly dividing lymphocytes in lymph nodules are called germinal centers.

Question 12

Which of the following statements about immunity is TRUE?

Accepted Answer

- A is true because the mediators of innate immunity, such as dendritic cells and cytokines, play a crucial role in activating and directing the adaptive immune response.
- B is true because many infections can cause swelling and inflammation of the lymph nodes, which are a key part of the lymphatic system.
- C is true because immunity refers to the body's ability to defend itself against a wide range of threats, both internal and external.
- D is true because the immune system is complex and involves interactions between different types of immune cells and molecules, including both innate and adaptive immunity.

Question 13

Which of the following is FALSE?

Accepted Answer

Helper T cells do not divide into cytotoxic T cells which produce antibodies. Helper T cells activate B cells to produce antibodies and also activate cytotoxic T cells.

Question 14

_____________ involves memory response.

Accepted Answer

All forms of adaptive immunity involve memory response. Memory response is the ability of the immune system to remember past infections and respond more quickly and effectively to subsequent infections with the same pathogen.

Question 15

The secondary,or memory immune response

Accepted Answer

The secondary or memory immune response has all of these properties. It prevents disease symptoms from occurring, causes B memory cells to rapidly divide to form plasma cells, produces more antibodies than during the primary response, and is faster than the primary response. This is because the body has already encountered the pathogen before and has memory cells ready to recognize and attack it more efficiently.

Question 16

Which of the following functions in positive feedback between the adaptive and innate immune responses?

Accepted Answer

Both cytotoxic T cell release of cytokines and release of antibodies by plasma B cells positively feedback to enhance the innate immune response. Cytokines released by T cells can activate macrophages and other immune cells, while antibodies produced by B cells can opsonize pathogens and enhance their destruction by phagocytes. This amplifies the immune response and helps to efficiently clear the infection. Proliferation of memory B cells is a part of the adaptive immune response but does not directly contribute to positive feedback with the innate immune response.

Question 17

Cell mediated immunity involves:

Accepted Answer

Cell mediated immunity is specifically related to the actions of T cells, which are responsible for recognizing and attacking infected or abnormal cells. B cells are involved in humoral immunity, which involves the production of antibodies. Natural Killer cells are important for innate immunity and can attack infected or cancerous cells without prior exposure. Antibodies are involved in humoral immunity and specifically target foreign substances, such as bacteria or viruses. Pyrogens are substances that can cause a fever and are not directly related to immune responses.

Question 18

Immunotherapy

Accepted Answer

Immunotherapy is a type of treatment that alters the function of the immune system to help it recognize and destroy cancer cells or other disease-causing pathogens. It is often used in cancer treatment to help the immune system attack and kill cancer cells, but can also be used for other diseases such as autoimmune disorders.

Question 19

In innate immunity,

Accepted Answer

Innate immunity provides a non-specific response that is the same each time the body is exposed to a particular substance, without the need for prior exposure or memory.

Question 20

_____________ involves production of cytokines.

Accepted Answer

The answer of _____________ involves production of cytokines.
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Quiz 14: The Lymphatic System and Immunity