Q1. Define the following terms: Acute, Chronic, Host, Iatrogenic, Idiopathic, Mutualism, Parasitism, Pathogenicity, Sequelae, Sign, Symptom, Syndrome, Virulence, & Virulence Factor.

Background

Topic: Infectious Disease Terminology

This question tests your understanding of key vocabulary used in microbiology and infectious disease. Knowing these definitions is essential for describing disease processes and interactions between microbes and hosts.

Key Terms:

• Acute: A disease with a rapid onset and/or a short course.

• Chronic: A disease that develops slowly and lasts for a long time.

• Host: The organism that harbors a pathogen.

• Iatrogenic: Resulting from medical treatment or procedures.

• Idiopathic: Of unknown cause.

• Mutualism: A relationship where both organisms benefit.

• Parasitism: A relationship where one organism benefits at the expense of the other.

• Pathogenicity: The ability of a microorganism to cause disease.

• Sequelae: Conditions resulting from a previous disease.

• Sign: Objective evidence of disease (observable by others).

• Symptom: Subjective evidence of disease (felt by the patient).

• Syndrome: A group of signs and symptoms that occur together.

• Virulence: The degree of pathogenicity.

• Virulence Factor: Molecules produced by pathogens that contribute to the pathogenicity.

Step-by-Step Guidance

1. Read each term carefully and try to recall its definition from your textbook or lecture notes.

2. For each term, think of an example or context in which it might be used (e.g., "acute infection" vs. "chronic infection").

3. Group similar terms together (e.g., "sign," "symptom," and "syndrome") to help remember their differences.

4. Write out each definition in your own words to reinforce your understanding.

5. For "virulence" and "virulence factor," consider how these relate to the ability of a microbe to cause disease and what specific molecules or mechanisms are involved.

Try defining each term on your own before revealing the answer!

Q2. What are the functions of hyaluronidase, collagenase, coagulase, staphylokinase, and streptokinase?

Background

Topic: Bacterial Enzymes as Virulence Factors

This question tests your knowledge of specific enzymes produced by bacteria that help them invade host tissues and evade immune responses.

Key Terms:

• Hyaluronidase: Breaks down hyaluronic acid in connective tissue.

• Collagenase: Breaks down collagen in connective tissue.

• Coagulase: Causes blood to clot.

• Staphylokinase/Streptokinase: Dissolve blood clots.

Step-by-Step Guidance

1. Recall what each enzyme targets in the host (e.g., connective tissue, blood clots).

2. Think about how breaking down these host components would help a pathogen spread or evade the immune system.

3. For coagulase, consider why a bacterium would want to form a clot around itself.

4. For staphylokinase and streptokinase, consider why dissolving clots would be advantageous for a pathogen.

5. Write a brief function for each enzyme, focusing on its role in pathogenesis.

Try matching each enzyme to its function before revealing the answer!

Q3. Differentiate between an endotoxin and an exotoxin.

Background

Topic: Bacterial Toxins

This question tests your understanding of the two main types of toxins produced by bacteria and their characteristics.

Key Terms:

• Endotoxin: Lipopolysaccharide (LPS) found in the outer membrane of Gram-negative bacteria.

• Exotoxin: Proteins secreted by bacteria (both Gram-positive and Gram-negative).

Step-by-Step Guidance

1. Recall the structural differences between Gram-positive and Gram-negative bacteria.

2. Think about where each toxin is located or produced (cell wall vs. secreted).

3. Consider the chemical nature of each toxin (protein vs. lipid-polysaccharide).

4. Think about the effects each toxin has on the host and how they are released.

5. Summarize the main differences in a table or list.

Try listing the differences before revealing the answer!

Q4. What are the virulence factors that are “antiphagocytic”?

Background

Topic: Bacterial Evasion of Host Defenses

This question tests your knowledge of how bacteria avoid being destroyed by phagocytes (cells that ingest and destroy microbes).

Key Terms:

• Antiphagocytic: Preventing or resisting phagocytosis.

• Virulence factors: Molecules that help bacteria evade immune responses.

Step-by-Step Guidance

1. Recall the main mechanisms bacteria use to avoid phagocytosis (e.g., capsules, certain proteins).

2. Think about how a capsule might prevent a phagocyte from recognizing or engulfing a bacterium.

3. Consider other surface molecules or secreted factors that interfere with phagocytosis.

4. List at least two examples of antiphagocytic virulence factors.

Try listing the antiphagocytic factors before revealing the answer!

Q5. What are the 5 stages of an infectious disease, their order, and what occurs during each phase?

Background

Topic: Course of Infectious Disease

This question tests your understanding of the progression of infectious diseases from initial exposure to recovery.

Key Terms:

• Incubation period

• Prodromal period

• Illness

• Decline

• Convalescence

Step-by-Step Guidance

1. List the five stages in order from first to last.

2. For each stage, write a brief description of what is happening in the host (e.g., symptoms, pathogen levels).

3. Think about which stage is most infectious and why.

4. Consider how the immune system responds during each stage.

5. Summarize the key features of each stage.

Try describing each stage before revealing the answer!

Q6. What are the 3 modes of contact transmission, the four modes of vehicle transmission, and the two modes of vector transmission?

Background

Topic: Epidemiology – Transmission of Infectious Agents

This question tests your knowledge of how infectious diseases are spread from one host to another.

Key Terms:

• Contact transmission: Direct, indirect, droplet

• Vehicle transmission: Airborne, waterborne, foodborne, bodily fluids

• Vector transmission: Biological, mechanical

Step-by-Step Guidance

1. List the three types of contact transmission and give an example of each.

2. List the four types of vehicle transmission and think about what "vehicle" means in this context.

3. List the two types of vector transmission and recall the difference between biological and mechanical vectors.

4. Write a brief description or example for each mode.

Try listing and describing each mode before revealing the answer!

Q7. Differentiate incidence from prevalence.

Background

Topic: Epidemiology – Disease Frequency

This question tests your understanding of how disease occurrence is measured in populations.

Key Terms:

• Incidence: Number of new cases in a specific time period.

• Prevalence: Total number of cases (new and existing) at a given time.

Step-by-Step Guidance

1. Recall the definitions of incidence and prevalence.

2. Think about what each measure tells you about a disease in a population.

3. Consider how each is calculated (numerator and denominator).

4. Write a sentence comparing the two.

Try defining and comparing these terms before revealing the answer!

Q8. Differentiate endemic, epidemic, pandemic, and sporadic.

Background

Topic: Epidemiology – Patterns of Disease Occurrence

This question tests your understanding of terms used to describe how diseases occur in populations.

Key Terms:

• Endemic: Constantly present in a population.

• Epidemic: Sudden increase in cases above normal.

• Pandemic: Epidemic that spreads over multiple countries or continents.

• Sporadic: Occurs occasionally and irregularly.

Step-by-Step Guidance

1. Recall the definition of each term.

2. Think about examples of diseases that fit each pattern.

3. Compare the scale and frequency of each type.

4. Write a brief description for each.

Try defining each term before revealing the answer!

Q9. Know the main function of each of the following cells and which are granulocytes/agranulocytes: Basophil/mast cell, eosinophil, lymphocyte, monocyte/macrophage, neutrophil.

Background

Topic: Innate Immunity – White Blood Cells

This question tests your knowledge of the different types of white blood cells, their functions, and their classification as granulocytes or agranulocytes.

Key Terms:

• Granulocytes: Neutrophils, eosinophils, basophils

• Agranulocytes: Lymphocytes, monocytes/macrophages

Step-by-Step Guidance

1. List each cell type and recall its main function in immunity.

2. Classify each as a granulocyte or agranulocyte.

3. Think about which cells are involved in allergic responses, parasitic infections, or phagocytosis.

4. Write a brief function for each cell type.

Try classifying and describing each cell before revealing the answer!

Q10. Differentiate central from peripheral lymphoid tissue.

Background

Topic: Immune System Organization

This question tests your understanding of where immune cells develop and where they function in the body.

Key Terms:

• Central (primary) lymphoid tissue: Sites where lymphocytes develop and mature.

• Peripheral (secondary) lymphoid tissue: Sites where immune responses are initiated.

Step-by-Step Guidance

1. Recall which organs are considered central lymphoid tissues (e.g., bone marrow, thymus).

2. Recall which organs are considered peripheral lymphoid tissues (e.g., lymph nodes, spleen, MALT).

3. Think about the main function of each type of tissue.

4. Write a brief comparison.

Try differentiating these tissues before revealing the answer!

Q11. What type of lymphocyte matures in the thymus?

Background

Topic: Lymphocyte Development

This question tests your knowledge of where different lymphocytes mature.

Key Terms:

• T lymphocytes (T cells): Mature in the thymus.

• B lymphocytes (B cells): Mature in the bone marrow.

Step-by-Step Guidance

1. Recall the two main types of lymphocytes and where each matures.

2. Think about the function of the thymus in the immune system.

3. Write the answer in a complete sentence.

Try recalling which lymphocyte matures in the thymus before revealing the answer!

Q12. Understand examples given for physical barriers to infection (skin, muco-ciliary escalator, lacrimal apparatus, etc.).

Background

Topic: Innate Immunity – Physical Barriers

This question tests your understanding of the body's first line of defense against pathogens.

Key Terms:

• Physical barriers: Structures that prevent pathogen entry.

• Examples: Skin, mucous membranes, cilia, tears.

Step-by-Step Guidance

1. List the main physical barriers to infection.

2. For each, describe how it prevents pathogen entry.

3. Think about how the muco-ciliary escalator and lacrimal apparatus work.

4. Write a brief explanation for each example.

Try describing each barrier before revealing the answer!

Q13. What are the steps of phagocytosis? What types of cells can carry it out?

Background

Topic: Innate Immunity – Phagocytosis

This question tests your understanding of how certain immune cells ingest and destroy pathogens.

Key Terms:

• Phagocytosis: The process by which cells engulf and digest particles.

• Phagocytes: Neutrophils, macrophages, dendritic cells.

Step-by-Step Guidance

1. List the main steps of phagocytosis in order.

2. For each step, briefly describe what happens.

3. Recall which cells are capable of phagocytosis.

4. Write a summary of the process.

Try listing the steps and cell types before revealing the answer!

Q14. What is the main job of eosinophils? Natural killer cells?

Background

Topic: Innate Immunity – Specialized Cells

This question tests your knowledge of the specific roles of eosinophils and natural killer (NK) cells in the immune response.

Key Terms:

• Eosinophils: Combat parasitic infections and participate in allergic responses.

• Natural killer (NK) cells: Destroy virus-infected and tumor cells.

Step-by-Step Guidance

1. Recall the main function of eosinophils in the immune system.

2. Recall the main function of NK cells.

3. Think about how each cell type recognizes and destroys its targets.

4. Write a brief description for each.

Try describing the main job of each cell before revealing the answer!

Q15. Know the 4 cardinal signs of inflammation and the major steps in the inflammatory process.

Background

Topic: Inflammation

This question tests your knowledge of the classic signs of inflammation and the sequence of events that occur during the inflammatory response.

Key Terms:

• Cardinal signs: Redness, heat, swelling, pain

• Inflammatory process: Sequence of events leading to these signs

Step-by-Step Guidance

1. List the four cardinal signs of inflammation.

2. Recall the main steps in the inflammatory process (e.g., vasodilation, increased permeability).

3. For each step, think about how it leads to one or more of the cardinal signs.

4. Write a brief summary of the process.

Try listing the signs and steps before revealing the answer!

Q16. What does lysozyme do? Where is it found? What do interferons do? What cells make interferons alpha, beta, and gamma?

Background

Topic: Innate Immunity – Antimicrobial Substances

This question tests your knowledge of important antimicrobial molecules and their sources.

Key Terms:

• Lysozyme: Enzyme that breaks down bacterial cell walls.

• Interferons: Proteins that interfere with viral replication.

Step-by-Step Guidance

1. Recall the function of lysozyme and where it is commonly found in the body.

2. Recall the function of interferons and their role in antiviral defense.

3. List the types of interferons and which cells produce each type.

4. Write a brief summary for each molecule.

Try describing the function and source of each before revealing the answer!

Q17. What is complement? What are the three ways that it is activated? What 3 things can it lead to (hint: one involves the membrane attack complex)?

Background

Topic: Innate Immunity – Complement System

This question tests your knowledge of the complement system, its activation pathways, and its effects.

Key Terms:

• Complement: Group of proteins that enhance immune responses.

• Activation pathways: Classical, alternative, lectin

• Outcomes: Opsonization, inflammation, cell lysis (membrane attack complex)

Step-by-Step Guidance

1. Recall what the complement system is and its general function.

2. List the three pathways by which complement can be activated.

3. List the three main outcomes of complement activation.

4. Write a brief explanation for each outcome.

Try listing the pathways and outcomes before revealing the answer!

Q18. Know the main difference between B lymphocytes and T lymphocytes with respect to the type of immune response each mediates (humoral versus cell-mediated; antibodies versus cytotoxic T cells and cytokines).

Background

Topic: Adaptive Immunity – B and T Cells

This question tests your understanding of the two main branches of adaptive immunity and the roles of B and T cells.

Key Terms:

• B lymphocytes (B cells): Mediate humoral immunity (antibody production).

• T lymphocytes (T cells): Mediate cell-mediated immunity (cytotoxicity, cytokines).

Step-by-Step Guidance

1. Recall the main function of B cells in the immune response.

2. Recall the main function of T cells.

3. Think about the difference between humoral and cell-mediated immunity.

4. Write a brief comparison.

Try comparing B and T cells before revealing the answer!

Q19. Define antigen, epitope, antigen receptor (what is it for B cells? For T cells?).

Background

Topic: Adaptive Immunity – Antigen Recognition

This question tests your understanding of how the immune system recognizes and responds to foreign molecules.

Key Terms:

• Antigen: Substance that elicits an immune response.

• Epitope: Specific part of an antigen recognized by immune cells.

• Antigen receptor: Molecule on B or T cells that binds antigen.

Step-by-Step Guidance

1. Define "antigen" and "epitope."

2. Recall what the antigen receptor is for B cells (BCR) and T cells (TCR).

3. Write a brief definition for each term.

Try defining each term before revealing the answer!

Q20. Properties of adaptive immune response (specificity, diversity, memory, self-tolerance). Differentiate specificity from diversity – understand the basic way in which diversity is achieved with a limited number of genes (recombination). Differentiate effector from memory cell and primary from secondary immune response. Define self-tolerance.

Background

Topic: Adaptive Immunity – Key Properties

This question tests your understanding of the unique features of adaptive immunity and how they are achieved.

Key Terms:

• Specificity: Ability to target specific antigens.

• Diversity: Ability to recognize many different antigens.

• Memory: Ability to respond more rapidly upon re-exposure.

• Self-tolerance: Ability to avoid attacking self tissues.

• Recombination: Genetic mechanism for generating diversity.

• Effector cell: Active cell that carries out immune response.

• Memory cell: Long-lived cell that responds to future exposures.

• Primary vs. secondary response: First vs. subsequent exposure to antigen.

Step-by-Step Guidance

1. List and define the four properties of adaptive immunity.

2. Differentiate specificity from diversity and explain how diversity is generated.

3. Differentiate effector from memory cells.

4. Differentiate primary from secondary immune responses.

5. Define self-tolerance.

Try explaining each property and difference before revealing the answer!

Q21. What is a plasma cell? For what type of lymphocyte is it an effector cell?

Background

Topic: Adaptive Immunity – Effector Cells

This question tests your knowledge of the role of plasma cells in the immune response.

Key Terms:

• Plasma cell: Antibody-secreting effector cell.

• B lymphocyte: Gives rise to plasma cells.

Step-by-Step Guidance

1. Recall what a plasma cell does in the immune system.

2. Recall which lymphocyte gives rise to plasma cells.

3. Write a brief answer.

Try recalling the function and origin of plasma cells before revealing the answer!

Q22. Know the three different types of T lymphocytes (aka T cells) and the main function of each. Which one expresses CD4? Which one expresses CD8? Which one binds to MHC class II? Which one binds to MHC Class I? Which one is a helper cell? Which one is a cytotoxic T cell? Which one kills cells infected with viruses and tumor cells?

Background

Topic: Adaptive Immunity – T Cell Subsets

This question tests your knowledge of the different types of T cells, their markers, and their functions.

Key Terms:

• Helper T cell (CD4+): Binds MHC class II, helps activate other immune cells.

• Cytotoxic T cell (CD8+): Binds MHC class I, kills infected/tumor cells.

• Regulatory T cell: Suppresses immune responses.

Step-by-Step Guidance

1. List the three main types of T cells and their main functions.

2. Recall which T cell expresses CD4 and which expresses CD8.

3. Recall which T cell binds to MHC class I and which to MHC class II.

4. Identify which T cell is a helper cell and which is cytotoxic.

5. Write a summary for each type.

Try matching each T cell type to its function and marker before revealing the answer!

Q23. What are cytokines? With what type of T cell are they associated?

Background

Topic: Adaptive Immunity – Cell Signaling

This question tests your knowledge of the signaling molecules used by immune cells and which T cells produce them.

Key Terms:

• Cytokines: Small proteins that mediate and regulate immunity.

• Helper T cells: Major producers of cytokines.

Step-by-Step Guidance

1. Define cytokines and their general function.

2. Recall which T cell type is most associated with cytokine production.

3. Write a brief answer.

Try defining cytokines and their source before revealing the answer!

Q24. What are perforins? With what type of T cell are they associated?

Background

Topic: Adaptive Immunity – Cytotoxic Mechanisms

This question tests your knowledge of how cytotoxic T cells kill infected cells.

Key Terms:

• Perforins: Proteins that create pores in target cell membranes.

• Cytotoxic T cells: Use perforins to kill infected cells.

Step-by-Step Guidance

1. Define perforins and their function in the immune response.

2. Recall which T cell type uses perforins.

3. Write a brief answer.

Try defining perforins and their association before revealing the answer!