Which row shows the type of reaction that occurs and the colour of the mixture at the end of the reaction?

Correct Answer: B

Rationale: The correct answer is B: neutralisation, yellow. In a neutralization reaction between an acid and a base, the acidic and basic properties neutralize each other, resulting in a salt and water. The indicator phenolphthalein is commonly used in acid-base titrations, turning pink in basic solutions and colorless in acidic solutions. When the reaction is complete and the solution is neutral (pH 7), phenolphthalein appears yellow. Therefore, the color of the mixture at the end of a neutralization reaction is yellow. Choices A, C, and D are incorrect because neutralization reactions typically result in a yellow color, not orange, and redox reactions do not involve the same color changes as neutralization reactions.

Correct Answer: B

Rationale: The correct answer is B: paracrine. Paracrine signaling involves the release of signaling molecules into the extracellular fluid to affect nearby target cells. This type of signaling is localized and affects cells within close proximity. Autocrine signaling (A) involves cells releasing signals that act on themselves, endocrine signaling (C) involves signaling molecules being released into the bloodstream to affect distant target cells, and neural signaling (D) involves the transmission of signals through neurons. In this case, paracrine signaling specifically targets local cells by releasing chemicals into the extracellular fluid, making it the correct choice.

Correct Answer: C

Rationale: Step 1: The congenital condition described points towards a disorder affecting growth and development. Step 2: The symptoms of mental retardation, short body size, and thick neck suggest hypothyroidism. Step 3: Thyroxin is a hormone produced by the thyroid gland that regulates metabolism and growth. Step 4: A deficiency of thyroxin in congenital hypothyroidism leads to the described symptoms. Step 5: Therefore, the correct answer is C: deficiency of thyroxin. Summary: A: Insulin deficiency does not match the symptoms described. B: Thymosin deficiency is not related to growth and mental retardation. D: Excess of synthetic growth hormone would not cause mental retardation and thick neck.

Correct Answer: C

Rationale: The left supra-renal vein drains into the left renal vein. This is because the left adrenal gland is located above the left kidney, and the left renal vein is responsible for draining blood from the left kidney and adjacent structures, including the left adrenal gland. Therefore, the correct answer is C. Incorrect options: A: The inferior vena cava receives blood from various veins in the body but not specifically from the left supra-renal vein. B: The inferior mesenteric vein drains the large intestine and does not receive blood from the left supra-renal vein. D: The superior mesenteric vein drains blood from the small intestine and does not receive blood from the left supra-renal vein. In summary, the left supra-renal vein drains into the left renal vein due to their anatomical proximity, making option C the correct answer.

Correct Answer: a

Rationale: The correct answer is A: Epimysium. Epimysium is the dense connective tissue layer that surrounds the entire muscle belly, providing structural support and protection. It separates the biceps femoris muscle from surrounding tissues. Perimysium (B) surrounds bundles of muscle fibers within the muscle belly, while endomysium (C) surrounds individual muscle fibers. Blood (D) is not a connective tissue layer but a fluid tissue responsible for transporting nutrients and waste products. Therefore, the epimysium is the correct choice as it specifically surrounds the biceps femoris muscle belly.