Which is not a good prognostic factor in ALL?

Correct Answer: A

Rationale: The correct answer is A: Mature B cell immunophenotype. In ALL, a mature B cell immunophenotype is associated with a poorer prognosis because it indicates that the leukemia cells have progressed to a more advanced stage of differentiation, making them more aggressive and resistant to treatment. On the other hand, choices B, C, and D are good prognostic factors in ALL. Female gender is associated with a better response to treatment, hyperploidy is a favorable genetic feature, and age 4-10 years is a common age group with a higher likelihood of responding well to treatment.

Correct Answer: B

Rationale: The correct answer is B: Irradiating blood components. This is because irradiation of blood components helps prevent graft-versus-host disease by inactivating T lymphocytes present in the transfused blood. This decreases the risk of these donor T cells attacking the recipient's tissues, which is the underlying mechanism of graft-versus-host disease. Explanation of other choices: A: Packed cells - While packed red blood cells are less likely to cause a reaction compared to whole blood, they do not prevent graft-versus-host disease. C: Fresh whole blood - Fresh whole blood does not address the specific mechanism of graft-versus-host disease prevention like irradiation does. D: Crystalloid replacement - Crystalloid replacement does not have any impact on preventing graft-versus-host disease as it does not affect the T lymphocytes present in the transfused blood components.

Correct Answer: C

Rationale: The correct answer is C: Temporary water in jungles. Anopheles balabacensis is a species of mosquito known to breed in temporary water sources found in jungles. They typically lay their eggs in small, shallow pools of water that form after rainfalls. This choice is correct because it aligns with the known breeding habits of this particular mosquito species. A: Artificial containers - Incorrect. Anopheles balabacensis typically does not breed in artificial containers but prefers natural water sources. B: Drains - Incorrect. This species does not usually breed in drains but rather in natural water bodies. D: Rock pools - Incorrect. Anopheles balabacensis prefers temporary water in jungles over rock pools for breeding due to the specific environmental conditions required for egg-laying and larval development.

Correct Answer: D

Rationale: Step-by-step rationale for why answer D is correct: 1. An antigen is a substance that stimulates the production of antibodies. 2. Antigens can be proteins, carbohydrates, or other molecules that the immune system recognizes as foreign. 3. Antigens trigger the immune system to produce antibodies to neutralize or eliminate the foreign substance. 4. Therefore, the correct answer is D as it accurately describes the role of antigens in stimulating antibody production. Summary: A, B, and C are incorrect because: A: Antigens are not proteins themselves but can be recognized by antibodies. B: Antigens do not inhibit microorganism growth; they stimulate immune responses. C: Antigens do not directly stimulate antibody production; they trigger the immune system to produce antibodies in response to foreign substances.

Correct Answer: A

Rationale: The correct answer is A because rivaroxaban is a direct factor Xa inhibitor that works by inhibiting thrombin formation. Thrombin is a key enzyme in the blood coagulation pathway, and by inhibiting it, rivaroxaban prevents the formation of fibrin clots. Choices B and D are incorrect because rivaroxaban does not directly inhibit fibrinogen or work against vitamin K. Choice C is also incorrect as rivaroxaban does not actually "thin" the blood but rather prevents the formation of clots by inhibiting thrombin.