Chronic lymphocytic leukemia is most common leukemia in what kind of people? Slide 4

Correct Answer: B

Rationale: The correct answer is B: Older adults. Chronic lymphocytic leukemia typically affects individuals over the age of 50, with the average age of diagnosis around 70. This type of leukemia is rare in young adults, children, or middle-aged adults. Risk factors for chronic lymphocytic leukemia include advanced age and a family history of the disease. Therefore, older adults are the most commonly affected demographic group for this type of leukemia.

Correct Answer: D

Rationale: The correct answer is D because the lipids in the RBC membrane are arranged in a phospholipid bilayer structure, with two layers that are not symmetric in composition. This asymmetry is crucial for maintaining the integrity and function of the membrane. The inner and outer layers have different lipid compositions, allowing for specific functions such as signal transduction and selective permeability. Choice A is incorrect because lipids are not arranged in chains beneath a protein exoskeleton in the RBC membrane. Choice B is incorrect because the hydrophobic portions of lipids face each other within the membrane, not the plasma. Choice C is incorrect as lipids are not arranged in a hexagonal lattice in the RBC membrane.

Correct Answer: B

Rationale: The correct answer is B because the globin chain genes are indeed located on separate chromosomes. The alpha (a) genes are located on one chromosome, while the beta (B) genes are located on a different chromosome. This arrangement allows for independent regulation and expression of the alpha and beta globin chains. Choices A, C, and D are incorrect because they do not accurately reflect the known genetic arrangement of the globin chain genes. Choice A incorrectly states that both a and B genes are on the same chromosome, which is not the case. Choice C is incorrect as it states that there are four a genes and four B genes, which is not accurate. Choice D is incorrect as it states that there are four a genes on one chromosome and two B genes on a different chromosome, which is also inaccurate.

Correct Answer: B

Rationale: The correct answer is B (25%). When both parents are carriers of the sickle cell trait, they each pass down the gene for sickle cell or normal hemoglobin with a 50% chance. The possible combinations are SS (normal), SS (sickle cell disease), AS (sickle cell trait), or AS (sickle cell trait). Therefore, there is a 25% chance (1 out of 4) that their child will inherit two sickle cell genes and have sickle cell anaemia. Choices A, C, and D are incorrect as they do not accurately reflect the genetic probability based on Mendelian inheritance principles.

Correct Answer: B

Rationale: The most likely diagnosis is B: Deep vein thrombosis (DVT). In a post-hip replacement patient with painful, pale, and swollen calf, DVT is common due to immobility and hypercoagulability. DVT presents with unilateral swelling, pain, and discoloration. Acute limb ischemia (A) typically presents with sudden severe pain, pallor, pulselessness, and paralysis. Cellulitis (C) presents with redness, warmth, and tenderness, not pallor. Fracture complication (D) would typically present with localized pain and swelling at the fracture site, not in the calf region.