Artemisinin and its derivatives are used in the treatment of severe forms of chloroquine-resistant falciparum because they have:

Correct Answer: D

Rationale: The correct answer is D: Rapid schizonticidal activity. Artemisinin and its derivatives target the asexual stage of the malaria parasite's life cycle, specifically the schizont stage. By quickly destroying the schizonts, they effectively kill the parasites in the blood, leading to a rapid reduction in parasite load and alleviating symptoms. The other choices are incorrect because A (Rapid gametocidal activity) targets sexual stage parasites, B (Ability to prevent further development of hypnozoites) refers to relapse prevention in Plasmodium vivax and Plasmodium ovale infections, and C (Rapid sporontocidal activity) targets the mosquito stage of the parasite's life cycle.

Correct Answer: C

Rationale: The correct answer is C: rheumatoid arthritis. In rheumatoid arthritis, there is chronic inflammation leading to elevated levels of ferritin (Fe) due to increased iron storage and a normal total iron-binding capacity (TIBC). This is because despite the increased iron stores, the body is unable to utilize it fully due to chronic inflammation. Incorrect choices: A: Thalassemia major would typically present with decreased TIBC due to increased iron absorption to compensate for the chronic anemia. B: Haemosiderosis would show elevated Fe but a decreased TIBC due to iron overload. D: Disseminated malignancy may show elevated Fe levels but typically with a decreased TIBC due to anemia of chronic disease.

Correct Answer: C

Rationale: The correct answer is C: clubbing. Plummer Vinson syndrome is characterized by the triad of dysphagia, iron deficiency anemia, and esophageal webs. Clubbing is not a typical feature of this syndrome. Angular stomatitis (A), splenomegaly (B), and post cricoid web (D) are all associated with Plummer Vinson syndrome. Angular stomatitis is due to iron deficiency anemia, splenomegaly can be present due to chronic anemia, and post cricoid web is a characteristic finding in the esophagus of patients with this syndrome.

Correct Answer: B

Rationale: Step 1: Cooley's anemia is another term for thalassemia major, a genetic disorder affecting hemoglobin production. Step 2: Thalassemia major results in severe anemia due to the body's inability to produce enough functional hemoglobin. Step 3: Sickle cell anemia (Choice A) is a different genetic disorder characterized by abnormal hemoglobin shape. Step 4: High ESR (Choice C) is a non-specific marker of inflammation, not specific to Cooley's anemia. Step 5: Aplastic anemia (Choice D) is a condition where the bone marrow does not produce enough blood cells, not specific to Cooley's anemia.

Correct Answer: C

Rationale: Step 1: Hepato-splenomegaly with lymphadenopathy is commonly seen in hematologic malignancies. Step 2: Chronic Myeloid Leukemia (CML) primarily presents with splenomegaly, but not lymphadenopathy. Step 3: Acute Lymphoblastic Leukemia (ALL), lymphoma, and disseminated TB can all present with these findings. Step 4: Therefore, the correct answer is C - CML, as it does not typically present with lymphadenopathy. Other choices are incorrect as they can present with these symptoms.