Oral iron supplements are given for iron deficiency anemia. Which of the statement is true regarding the absorption of oral iron supplements?

Correct Answer: A

Rationale: Rationale: A: Correct - Iron absorption primarily occurs in the duodenum and upper small intestine, not the large intestine. B: Incorrect - Intrinsic factor is necessary for Vitamin B12 absorption, not iron. C: Incorrect - Ascorbic acid (Vitamin C) actually enhances iron absorption. D: Incorrect - Absorption is decreased in hereditary hemochromatosis, a condition of iron overload.

Correct Answer: D

Rationale: The correct answer is D because heparin binds to antithrombin III, enhancing its ability to inactivate thrombin. This prevents the conversion of fibrinogen to fibrin, thereby inhibiting blood clot formation. Choices A and B are incorrect because heparin does not affect vitamin K-dependent clotting factors or platelet activation. Choice C is incorrect because heparin does not directly prevent platelet aggregation.

Correct Answer: D

Rationale: The correct answer is D, as the Philadelphia chromosome is typically found in myeloid cells, not lymphocytes. This is because the Philadelphia chromosome results from a translocation between chromosomes 9 and 22, leading to the formation of the BCR-ABL fusion gene, which is associated with chronic myeloid leukemia (CML). Choice A is correct as the Philadelphia chromosome results from the shortening of the long arm of chromosome 22. Choice B is incorrect as Philadelphia positivity in CML patients is associated with a worse prognosis. Choice C is correct as the presence of the Philadelphia chromosome is a diagnostic hallmark of CML.

Correct Answer: C

Rationale: The correct answer is C, pernicious anemia. Pernicious anemia is a macrocytic anemia caused by vitamin B12 deficiency affecting red blood cell production. Sideroblastic anemia (A), thalassemia (B), and lead poisoning (D) can all lead to microcytic anemia due to different mechanisms such as impaired hemoglobin synthesis or red blood cell destruction. Pernicious anemia, on the other hand, is not associated with microcytosis.

Correct Answer: C

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.