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Question 1:

Which of the following is responsible for recognizing and attacking foreign substances in the body?

A) Antibodies
B) T cells
C) B cells
D) Phagocytes

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Explanation: The correct answer is D) Phagocytes. Phagocytes, including macrophages and neutrophils, are cells of the immune system responsible for recognizing and engulfing foreign substances, such as bacteria or viruses, through a process called phagocytosis.

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Question 2:

Which type of immunity is acquired through the production of antibodies in response to an infection or vaccination?

A) Innate immunity
B) Passive immunity
C) Adaptive immunity
D) Humoral immunity

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Explanation: The correct answer is C) Adaptive immunity. Adaptive immunity is the type of immunity that develops over time as a result of exposure to specific pathogens or antigens. It involves the production of antibodies by B cells and the activation of T cells to provide long-term protection against future infections.

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Question 3:

Which cells of the immune system are responsible for coordinating the immune response?

A) Antibodies
B) T cells
C) B cells
D) Helper T cells

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Explanation: The correct answer is D) Helper T cells. Helper T cells play a critical role in coordinating the immune response. They recognize antigens presented by antigen-presenting cells and help activate other immune cells, such as B cells and cytotoxic T cells, to eliminate the pathogen.

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Question 4:

Which cells of the immune system are responsible for directly killing infected cells?

A) Antibodies
B) T cells
C) B cells
D) Natural killer cells

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Explanation: The correct answer is D) Natural killer cells. Natural killer cells are a type of lymphocyte that can recognize and kill infected cells, as well as tumor cells, without the need for prior activation or specific antigen recognition. They play an important role in the innate immune response.

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Question 5:

Which of the following is an example of an autoimmune disease?

A) Influenza
B) Tuberculosis
C) Rheumatoid arthritis
D) Malaria

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Explanation: The correct answer is C) Rheumatoid arthritis. Rheumatoid arthritis is an autoimmune disease in which the immune system mistakenly attacks the body's own tissues, particularly the joints, resulting in inflammation, pain, and joint damage.