Nokea
What is the most common cause of secondary immunodeficiency disorders?
- A. Chronic stress
- B. T-cell deficiency from HIV
- C. Drug-induced immunosuppression
- D. Common variable hypogammaglobulinemia
Correct Answer: C
Rationale: Drug-induced immunosuppression is a frequent cause of secondary immunodeficiency, often due to medications used in treating other conditions.
You may also like to solve these questions
T cell receptor and B cell receptor genes both undergo:
- A. Somatic hypermutation
- B. Germline gene rearrangement
- C. Isotype switching
- D. Both A and B are correct
Correct Answer: B
Rationale: The correct answer is B, germline gene rearrangement. T cell receptor and B cell receptor genes both undergo germline gene rearrangement during lymphocyte development, where gene segments are rearranged to generate diverse antigen receptor specificities. Somatic hypermutation and isotype switching are processes specific to B cells in the adaptive immune response, not T cells. Therefore, choices A and C are incorrect. Choice D is incorrect as well since somatic hypermutation is not a process involved in T cell receptor gene rearrangement.
Thymocytes undergoing positive selection express:
- A. TCR
- B. CD4
- C. CD8
- D. All of the above
Correct Answer: D
Rationale: Thymocytes undergoing positive selection express both CD4 and CD8 co-receptors along with a functional T-cell receptor (TCR). CD4 and CD8 help in recognizing MHC molecules, while TCR is crucial for antigen recognition. Positive selection ensures that thymocytes with a functional TCR that can interact with self-MHC molecules survive. Therefore, the correct answer is D, as thymocytes undergoing positive selection express TCR, CD4, and CD8. Choice A, TCR alone, is incorrect as CD4 and CD8 are also expressed. Choices B and C are incorrect as positive selection involves the expression of both CD4 and CD8, not just one or the other.
Ferrets have recently been objects of an intense debate within the scientific community in the field of Flu research because
- A. Of a recent outbreak caused by a novel Influenza strain
- B. Of a recent outbreak caused by a highly virulent H1N1 strain
- C. Mutations have been introduced in H5N1 creating a strain transmissible among these mammals
- D. Two publications on this animal model for Flu were put on hold due to biosecurity reasons
Correct Answer: C
Rationale: The correct answer is C because it indicates a specific reason for the intense debate within the scientific community regarding ferrets in Flu research. Mutations in H5N1 creating a strain transmissible among ferrets is significant as it highlights a potential threat of cross-species transmission and the need for further study.
A is incorrect as it does not provide a specific reason related to ferrets and their role in Flu research. B is incorrect because it focuses on a specific strain (H1N1) rather than mutations in H5N1. D is incorrect as it mentions publications being put on hold but does not address the core issue of mutations and transmissibility among ferrets.
Phagocytosis is not a characteristic of which groups?
- A. protozoans
- B. algae
- C. fungi
- D. Archaea
Correct Answer: D
Rationale: Phagocytosis is a process where cells engulf and digest particles. Archaea lack membrane-bound organelles, including phagosomes, making phagocytosis impossible. Protozoans, algae, and fungi have the necessary cellular structures for phagocytosis. Therefore, the correct answer is D. Protozoans, algae, and fungi can perform phagocytosis due to their cellular structure and function, making choices A, B, and C incorrect.
To produce better flu vaccines we want:
- A. To block spreading of the infection by inducing a cytotoxic T cell response that would directly prevent viral entry into uninfected cells
- B. To induce the formation of highly strain-specific neutralizing antibodies that would prevent viral entry into uninfected cells
- C. To induce antibodies able to recognize HA across different strains by targeting less variable regions of HA
- D. All of the above is reasonably expected to improve the success of flu vaccines
Correct Answer: C
Rationale: The correct answer is C because inducing antibodies that can recognize the less variable regions of the Hemagglutinin (HA) protein across different strains allows for cross-protection against various flu strains. This approach is effective as it targets conserved regions of the virus, increasing the likelihood of providing broad immunity. Option A focuses on cytotoxic T cell response, which primarily targets infected cells and may not prevent viral entry into uninfected cells. Option B, on the other hand, is limited to highly strain-specific neutralizing antibodies, which may not provide adequate protection against evolving flu strains. Therefore, option C is the most effective in producing better flu vaccines by targeting less variable regions of HA for broader immunity.