What is the formula of aluminium sulfate?

Correct Answer: A

Rationale: The correct formula for aluminium sulfate is Al2(SO4)3. This is because aluminium has a 3+ charge while sulfate has a 2- charge, requiring two aluminium ions to balance three sulfate ions. Choice B (Al2(SO3)4) is incorrect because sulfate ions have a 2- charge, not sulfite ions (SO3). Choices C (Al4(SO4)2) and D (Al4(SO3)2) have incorrect subscripts for the elements, not following the correct charge balance.

Correct Answer: A

Rationale: The correct answer is A: glucose-containing hormones. Hormones are classified based on their chemical structure, and glucose-containing hormones do not fit into any of the main categories (steroid, protein-based, amino acid-based). Glucose is a sugar molecule and not typically found as the primary chemical structure of hormones. Steroid hormones are derived from cholesterol, protein-based hormones are made of amino acids, and amino acid-based hormones are derived from single amino acids or peptides. Therefore, glucose-containing hormones do not align with the traditional chemical classifications of hormones.

Correct Answer: A

Rationale: The correct answer is A: half-life. Water-soluble hormones have a shorter half-life compared to lipid-soluble hormones because they are quickly metabolized and excreted from the body. The other choices are incorrect because: B: Activation time is not directly related to the solubility of hormones. C: The size of the hormone molecule doesn't determine its solubility in water. D: The chain of amino acids may vary in different types of hormones, but it doesn't necessarily dictate their solubility.

Correct Answer: D

Rationale: Step 1: The pancreas is an elongated organ located behind the stomach. Step 2: The tail of the pancreas is the left end of the organ and is closest to the hilum of the spleen. Step 3: The spleen and the tail of the pancreas are adjacent to each other in the upper left quadrant of the abdomen. Step 4: Therefore, the correct answer is D: Tail. Summary: - A: Head is incorrect as it is the right end of the pancreas, farther away from the spleen. - B: Neck is incorrect as it is the narrow portion between the head and body, not near the spleen. - C: Body is incorrect as it is the central and longest part of the pancreas, not near the spleen. - D: Tail is correct as it is the left end of the pancreas, nearest to the hilum of the spleen.

Correct Answer: B

Rationale: The correct answer is B: Proximal part of dorsal pancreatic bud. The accessory pancreatic duct originates from the dorsal pancreatic bud during embryonic development. This is because the dorsal pancreatic bud gives rise to the body and tail of the pancreas, which includes the accessory pancreatic duct. The proximal part of the dorsal pancreatic bud specifically gives rise to the proximal part of the accessory pancreatic duct. Choices A, C, and D are incorrect because they refer to the distal part of the dorsal pancreatic bud, the distal part of the ventral pancreatic bud, and the proximal part of the ventral pancreatic bud, respectively, which are not associated with the origin of the accessory pancreatic duct.