Question 1

Which of the following best describes the concept of 'vector competence' in mosquitoes?

Accepted Answer

A mosquito’s genetic ability to acquire, maintain, and transmit a pathogen.

Question 2

A field program reports that a mosquito population shows no measurable change in intrinsic susceptibility to dengue infection, yet community-level transmission drops sharply after a microbiome-based intervention. Which interpretation best explains this finding?

Accepted Answer

The intervention reduced vectorial capacity without necessarily changing vector competence.

Question 3

Which of the following is NOT a mechanism by which the mosquito microbiome can reduce pathogen transmission?

Accepted Answer

Increasing the mosquito’s reproductive rate to outcompete pathogens.

Question 4

Which equation best represents the relationship between vectorial capacity ($$C$$), vector competence ($$b$$), mosquito density ($$m$$), biting rate ($$a$$), and mosquito lifespan ($$p) in $$the context of disease transmission?

Accepted Answer

$$C = \frac{ma^2$bp^n}{-\ln p}$$

Question 5

Which of the following statements about Wolbachia is most accurate?

Accepted Answer

Wolbachia is maternally inherited and can spread through mosquito populations via cytoplasmic incompatibility.

Question 6

A researcher claims that because a mosquito carries Wolbachia, it must always become a poorer vector exclusively due to immune activation. Why is this conclusion incomplete?

Accepted Answer

Wolbachia can both prime immunity and compete with pathogens for lipids and intracellular resources.

Question 7

Which of the following best explains how certain Enterobacter strains in the mosquito midgut can inhibit Plasmodium (malaria) parasites?

Accepted Answer

By secreting reactive oxygen species (ROS) such as hydrogen peroxide that are toxic to Plasmodium.

Question 8

A mosquito colony is treated with broad-spectrum antibiotics, eliminating vitamin-producing gut symbionts. Unexpectedly, dengue replication decreases rather than increases. Which lecture-based explanation best fits this result?

Accepted Answer

Loss of microbial nutrient provisioning weakened mosquito metabolism required for viral replication.

Question 9

Which statement most accurately distinguishes Wolbachia-based population replacement from Singapore’s IIT-SIT strategy?

Accepted Answer

Population replacement depends on maternal inheritance and spread through populations, whereas IIT-SIT relies on release of infected males to suppress reproduction.

Question 10

Which of the following is a direct effect of the mosquito microbiome on the mosquito’s immune system?

Accepted Answer

It primes the immune system by maintaining basal immune activity.

Question 11

Why is the presence of all four Dengue serotypes (DENV 1–4) in a region particularly dangerous for public health?

Accepted Answer

It increases the likelihood of antibody-dependent enhancement (ADE), raising the risk of severe dengue upon secondary infection.

Question 12

Which of the following best describes the mechanism by which Wolbachia blocks Dengue virus replication in Aedes aegypti?

Accepted Answer

Wolbachia sequesters host lipids and cholesterol, starving the virus and preventing its replication.

Question 13

Which of the following is an example of paratransgenesis as a vector control strategy?

Accepted Answer

Genetically engineering midgut bacteria to express anti-parasitic molecules that kill pathogens.

Question 14

A new antiviral drug for Dengue, Mosnodenvir, is in clinical trials. It works by blocking the interaction between viral proteins NS3 and NS4B. What is the most likely effect of this mechanism?

Accepted Answer

It stops the virus from replicating its genome inside human cells.

Question 15

Which of the following best explains why microbiome-based interventions are considered more sustainable than traditional insecticide spraying for mosquito control?

Accepted Answer

Microbiome interventions are self-sustaining and do not rely on repeated chemical applications.

Question 16

Which of the following is a plausible reason why removing vitamin-producing gut bacteria from mosquitoes could reduce their competence for Dengue virus transmission?

Accepted Answer

The mosquito’s metabolism becomes too weak to support viral replication due to lack of B vitamins.

Question 17

Which of the following is a real-world example of resource competition between mosquito symbionts and pathogens?

Accepted Answer

Wolbachia sequesters host lipids, reducing the resources available for Dengue virus replication.

Question 18

Which of the following best describes the concept of 'paratransgenesis'?

Accepted Answer

Genetically engineering symbiotic bacteria to express molecules that kill pathogens inside the mosquito.

Question 19

Which of the following is a key reason why the introduction of Wolbachia into Aedes aegypti populations has been successful in reducing Dengue transmission?

Accepted Answer

Wolbachia is transmitted maternally and spreads through populations via cytoplasmic incompatibility.

Lec 27: The Mosquito Microbiome and Its Impact on Vector Competence

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