Aplastic anemia can be induced by drugs such as Lithium, acetazolamide and aspirin

Correct Answer: B

Rationale: Step-by-step rationale: 1. Aplastic anemia is a rare disorder characterized by bone marrow failure. 2. While some drugs can cause bone marrow suppression, the mentioned drugs are not typically associated with aplastic anemia. 3. Lithium is linked to neutropenia, acetazolamide to aplastic anemia in rare cases, and aspirin to thrombocytopenia, not aplastic anemia. 4. Therefore, the correct answer is B: FALSE. Summary: - Choice A is incorrect because the drugs listed do not commonly induce aplastic anemia. - Choice C is incorrect as there is limited evidence supporting these drugs as common causes. - Choice D is incorrect as aplastic anemia induced by these drugs is not considered rare.

Correct Answer: A

Rationale: The correct answer is A: 70% alcohol or lens cleaner. Alcohol is recommended as it effectively removes oil without damaging the lens. Step 1: Apply alcohol on a clean cloth. Step 2: Gently wipe the lens in a circular motion. Alcohol evaporates quickly, leaving no residue. Xylene (B) is too harsh and can damage the lens. Water (C) can cause streaks and not effectively remove oil. Benzene (D) is toxic and should never be used on optical lenses.

Correct Answer: D

Rationale: Step 1: The Medullary Phase starts in the 6th week of gestation. Step 2: Hematopoiesis starts in the yolk sac and then moves to the liver, spleen, and bone marrow. Step 3: The clavicle is the first bone to show hematopoietic activity during this phase due to its unique development timeline. Step 4: Other choices like the femur, iliac crest, and skull develop hematopoietic activity later in fetal development. Summary: The clavicle is the correct answer as it is the first bone to exhibit hematopoietic activity during the Medullary Phase, while the other choices develop this activity later in the developmental process.

Correct Answer: D

Rationale: The correct answer is D because RBC precursors are located surrounding macrophages near the sinus membrane in the bone marrow. This location allows for the interaction between macrophages and developing RBCs, facilitating the removal of nuclei from maturing RBCs. Choices A, B, and C are incorrect because RBC precursors are not typically found in the center of hematopoietic cords, adjacent to megakaryocytes, or surrounding fat cells in apoptotic islands in the bone marrow.

Correct Answer: B

Rationale: Step-by-step rationale for the correct answer (B): 1. Low Hb (120 g/L) and MCV (69 fL) indicate microcytic anemia. 2. High WCC (14.9 x 10^9/L) suggests an inflammatory response. 3. Ferritin (18 ng/mL) is low, indicating iron deficiency. 4. Symptoms of blood in stools, fatigue, weight loss are concerning for colorectal cancer. 5. Therefore, the correct diagnosis is iron deficiency anemia due to colorectal cancer. Summary of incorrect choices: A: Iron deficiency anemia due to poor diet - Ferritin levels would typically be low in this case, but other results do not support this choice. C: Vitamin B12 deficiency due to pernicious anemia - MCV is low, not high as expected in vitamin B12 deficiency. D: Thalassemia due to genetic mutation - Thalassemia would present with microcytic anemia