BIO 251 EXAM 3 NEWEST 2024-2025 ACTUAL EXAM

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BIO 251 EXAM 3 NEWEST 2024-2025 ACTUAL EXAM

COMPLETE 100 QUESTIONS AND CORRECT

DETAILED ANSWERS (VERIFIED ANSWERS )

|ALREADY GRADED A+

An HIV positive individual with low CD4 T-cell count is infected with a normally non-fatal virus and later dies. What likely occurred?

• They were unable to generate antibodies through the T-dependent

pathway due to lack of helper T-cells

• Their immune system became hyper-active through the T-

independent pathway and they died due to a cytokine storm

• Their macrophages were unable to stimulate Helper T-cells due to

insufficient MHCII

• They were unable to release histamine and could not mount an

inflammatory response - ANSWER- A. They were unable to generate antibodies through the T-dependent pathway due to lack of helper T- cells

Suppose you are observing a patient who has a bacterial infection that begins to subside fairly quickly after becoming symptomatic. An analysis of their blood shows high levels of IgM specific to the bacteria, but undetectable levels of IgG and IgD. Two months after being discharged, the patient returns with another infection by the same bacteria. What would be reasonable to conclude?

• The patient's immune response was coordinated via cell-mediated

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• The patient is immunocompromised
• The patient's immune reaction happened through the T-independent

pathway

• The patient did not produce sufficient antibodies to fight off the first

infection - ANSWER- C. The patient's immune reaction happened through the T-independent pathway

Suppose that an antibody binds to a toxin molecule and prevents the toxin from binding to a receptor where it would have a negative effect.

This is an example of:

Immobilization Opsonization Neutralization Cross-linking - ANSWER- Neutralization

Which of the following is NOT a way that antibodies assist the immune system in getting rid of pathogens?

• Binding to viral coat proteins and preventing them from being able to

enter cells

• Labeling pathogens for phagocytosis
• Binding to flagella and fimbrae and preventing movement and

adherence.

• Poking holes in the cell membrane and lysing bacteria directly -

ANSWER- D. Poking holes in the cell membrane and lysing bacteria directly

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Which of the following would be an example of a PAMP?

Correct answer:

• Peptidoglycan
• Tissue factor
• GaGs on the surface of eukaryotic cells
• C3b bound to bacteria - ANSWER- A. Peptidoglycan

Match the antibody with the correct description Antibody involved in allergic reactions Antibody found abundantly in mucous secretions First antibody produced in response to an infection Antibody with poorly understood function Antibody that penetrates the placenta IgG IgE IgA IgM IgD - ANSWER- Antibody involved in allergic reactions

Correct match:

IgE Antibody found abundantly in mucous secretions

Correct match:

IgA 3 / 4

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First antibody produced in response to an infection

Correct match:

IgM Antibody with poorly understood function

Correct match:

IgD Antibody that penetrates the placenta

Correct match:

IgG

What event during inflammation is responsible for swelling?

• Vasodilation
• Diapedesis
• Increased sensitivity of nociceptors
• Increasing vascular permeability - ANSWER- D. Increasing vascular

permeability

Can't add this question for quizlet but know the names of the parts of phagocytosis. - ANSWER-

Put the steps of phagocytosis in order Chemotaxis Engulfment (endocytosis) Exocytosis

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