Question 1

Which of the following best describes the difference between innate and adaptive immunity in animals?

Accepted Answer

Innate immunity provides a rapid, non-specific response using a small set of receptors, while adaptive immunity provides a slower, highly specific response using a vast array of receptors.

Question 2

Which white blood cell is primarily responsible for phagocytosis and acts as an early responder to infection?

Accepted Answer

Neutrophil

Question 3

A parasite that lives inside host cells, such as Leishmania, is most likely to evade which component of the immune system?

Accepted Answer

Humoral response of adaptive immunity

Question 4

Which immunoglobulin is most involved in defense against large parasites, such as Schistosoma, and triggers eosinophil activation?

Accepted Answer

IgE

Question 5

What is the primary function of cytotoxic T-cells in the adaptive immune system?

Accepted Answer

Lyse infected or cancerous cells by recognizing antigens presented by MHC class I molecules

Question 6

Which equation best represents the relationship between antibody concentration and time after exposure to an antigen, as seen in immunological memory?

Accepted Answer

Antibody concentration increases rapidly after second exposure: $$C(t) = C_0$ + C_1$ e$$^{kt}$$, where C_1$ is much larger after secondary exposure

Question 7

Trypanosoma brucei evades the host immune system by regularly changing its surface coat proteins. What is this process called?

Accepted Answer

Antigenic variation

Question 8

Which of the following is a real-world example of an evolutionary arms race between host and parasite?

Accepted Answer

Cabbage White Butterflies evolving detoxification mechanisms for mustard plant glucosinolates

Question 9

What is the role of helper T-cells (TH) in the adaptive immune response?

Accepted Answer

Amplify the immune response by activating B-cells and cytotoxic T-cells, and are essential for memory cell formation

Question 10

Which mechanism allows Schistosoma mansoni to block complement and antibody action?

Accepted Answer

Mechanical blocking by cuticle and mimicry of Decay Accelerating Factor (DAF)

Question 11

A host's immune system can be manipulated by parasites in several ways. Which of the following is NOT a method used by parasites?

Accepted Answer

Enhancement of lysosomal toxic action

Question 12

Which cell type is responsible for presenting antigens to helper T-cells via MHC class II molecules?

Accepted Answer

Macrophages and dendritic cells

Question 13

In the context of brood parasitism, what adaptation have cuckoos evolved to increase their success in host nests?

Accepted Answer

Eggs that mimic the host's eggs and chick morphology resembling host chicks

Question 14

Which equation best describes the probability of a host nest producing at least one fledgling in the presence of a brood parasite, based on Canestrari et al. (2014)?

Accepted Answer

Probability is equal for parasitized and non-parasitized nests: $$P_{parasitized} \approx P_{non-parasitized}$$

Question 15

Which of the following is a consequence of coevolution between host and parasite, as demonstrated by Paterson et al. (2010)?

Accepted Answer

Higher rate of parasite evolution and changes in genes involved with host infection

Question 16

Which of the following best explains why Plasmodium merozoites are effectively 'safe' from the immune system when inside red blood cells?

Accepted Answer

Red blood cells lack MHC class I molecules, preventing cytotoxic T-cell recognition

Question 17

Which of the following is NOT a function of antibodies (immunoglobulins) in the immune response?

Accepted Answer

Direct lysis of infected cells

Question 18

Which cell type matures in the thymus and is involved in cell-mediated immunity?

Accepted Answer

T-cells

Question 19

Which of the following is a plausible reason why some hosts have not evolved defenses against brood parasites?

Accepted Answer

Brood parasitism is a recent evolutionary event for those hosts

Question 20

Which of the following is a multi-step mechanism by which the immune system responds to a pathogen, as illustrated in the humoral response?

Accepted Answer

Antigen is ingested by a macrophage, presented via MHC class II, activates helper T-cells, which then activate B-cells to produce antibodies

Parasite lec 10

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