Correct Answer: D

Rationale: Colon cancer is more likely associated with blood in stool due to the presence of bleeding from the tumor in the colon. Gastroesophageal reflux (Choice A) typically presents with heartburn and regurgitation but not blood in stool. Crohn's disease (Choice B) can cause gastrointestinal symptoms, but bloody stools are more commonly associated with ulcerative colitis. Irritable bowel syndrome (Choice C) is characterized by abdominal pain, bloating, and changes in bowel habits, but it does not typically cause blood in stool. Therefore, the correct answer is D, Colon cancer.

Correct Answer: B

Rationale: The correct answer is that the person is a sickle cell carrier. In HbAS, 'Hb' stands for hemoglobin, 'A' indicates normal hemoglobin, and 'S' indicates the sickle cell trait. Individuals with HbAS are carriers of the sickle cell trait but do not have sickle cell disease. Choice A is incorrect because having the sickle cell trait means carrying the gene for sickle cell disease. Choice C is incorrect as sickle cell anemia is a different condition where individuals have two copies of the abnormal hemoglobin gene, resulting in the disease. Choice D is incorrect because thalassemia is a separate genetic disorder affecting the production of hemoglobin, not related to the sickle cell trait.

Correct Answer: D

Rationale: The correct answer is 'Low-density lipoprotein (LDL) receptor mutation with defects in breakdown.' Primary hypercholesteremia is mainly caused by mutations in the LDL receptor, leading to impaired clearance of LDL cholesterol from the blood. This results in high levels of LDL cholesterol in the bloodstream. Choices A, B, and C are incorrect because they do not directly relate to the primary cause of primary hypercholesteremia.

Correct Answer: A

Rationale: The correct answer is A. In active transport, energy is expended to move substances against their concentration gradient. Sodium moving out of cells and potassium moving into cells is an example of active transport because it requires energy to pump these ions across the cell membrane against their concentration gradients. Choices B, C, and D describe passive processes where substances move along their concentration gradients without the input of energy.

Correct Answer: D

Rationale: Anemia of chronic inflammation is typically characterized by normochromic (normal hemoglobin content) and normocytic (normal cell size) red blood cells. Choice A, hypochromic and microcytic, is incorrect because hypochromic refers to reduced hemoglobin content and microcytic refers to smaller than normal red blood cells, which are not typically seen in anemia of chronic inflammation. Choice B, hypochromic and macrocytic, is also incorrect as macrocytic refers to larger than normal red blood cells. Choice C, normochromic and microcytic, is incorrect because microcytic red blood cells are smaller than normal. Therefore, the correct classification for anemia of chronic inflammation is normochromic and normocytic.