Bone marrow responds to iron therapy by increasing erythropoietic activity. Which of the following in bone marrow would most likely indicate erythropoiesis?

Correct Answer: B

Rationale: The correct answer is B: Reticulocytes. Reticulocytes are immature red blood cells released by the bone marrow into the bloodstream in response to increased erythropoietic activity. They indicate ongoing erythropoiesis as they mature into fully functional red blood cells. Myelocytes (A) are immature granulocytic precursors, not involved in erythropoiesis. Ring sideroblasts (C) are seen in conditions like sideroblastic anemia and indicate abnormal iron metabolism. Target cells (D) are red blood cells with a central bull's eye appearance and are associated with conditions like liver disease and thalassemias, not specifically erythropoiesis.

Correct Answer: C

Rationale: The correct answer is C because Anopheles balabacensis, the main vector transmitting malaria in Sabah, breeds in temporary water collections in jungles. This is supported by research showing that this mosquito species prefers breeding in natural habitats like jungle pools. Choices A, B, and D are incorrect because Anopheles balabacensis is not typically found breeding in artificial containers in urban centers, drains, or rock pools in control areas. These habitats do not provide the specific environmental conditions required for the breeding and survival of this particular mosquito species.

Correct Answer: D

Rationale: The correct answer is D: haemolysis. In thalassemia, there is an increased breakdown of red blood cells leading to excessive production of bilirubin causing jaundice. Viral hepatitis B and C do not directly cause jaundice in thalassemia. Iron deposition in the liver is seen in iron overload conditions like hemochromatosis, not thalassemia. Haemolysis in thalassemia is the primary reason for jaundice.

Correct Answer: C

Rationale: Basophilic stippling is caused by the presence of ribosomal RNA in red blood cells, which is a characteristic finding in chronic lead poisoning. Lead inhibits enzymes involved in heme synthesis, leading to accumulation of ribosomal RNA. In CML, there is an increase in immature white blood cells, not red blood cells. Myelosclerosis is associated with bone marrow fibrosis, not basophilic stippling. Iron deficiency anemia presents with microcytic, hypochromic red blood cells, not basophilic stippling.

Correct Answer: D

Rationale: The correct answer is D: hereditary spherocytosis. Splenectomy is curative in hereditary spherocytosis because the spleen is responsible for the destruction of the abnormal spherocytes in this condition. Removing the spleen eliminates the primary site of red blood cell destruction, leading to an improvement in anemia and other symptoms. Incorrect choices: A: Splenectomy is contraindicated in G6PD deficiency as it can worsen hemolysis by increasing the workload on other organs. B: Splenectomy can be beneficial in ITP to increase platelet counts but is not curative as the underlying autoimmune process persists. C: Splenectomy is not curative in thalassemia as it does not address the underlying genetic defect causing abnormal hemoglobin synthesis.