Nursing Elites

1. The feedback loop is a crucial concept in endocrine regulation. In a negative feedback loop, high levels of a hormone can:

• A. Further stimulate the release of the same hormone
• B. Inhibit the release of the hormone or its production
• C. Have no effect on the hormone's regulation
• D. Increase the need for another hormone entirely

Correct answer: B

Rationale: In a negative feedback loop, high levels of a hormone signal the body to stop producing more of that hormone in order to maintain homeostasis. This is a self-regulating mechanism to prevent excessive levels of the hormone. Option B is correct because in this scenario, the high levels of the hormone will inhibit its further release or production. This feedback loop helps ensure that hormone levels stay within a narrow range, preventing overstimulation or imbalance in the endocrine system. Options A, C, and D are incorrect as they do not align with the concept of negative feedback regulation in endocrine systems.

2. What is an example of a fibrous protein?

• A. Insulin
• B. Keratin
• C. Hemoglobin
• D. Collagen

Correct answer: D

Rationale: Rationale: A) Insulin is a hormone, not a fibrous protein. Insulin is produced in the pancreas and is involved in regulating blood sugar levels. B) Keratin is a fibrous structural protein found in hair, nails, and the outer layer of skin. It provides strength and protection. C) Hemoglobin is a globular protein found in red blood cells that is responsible for carrying oxygen from the lungs to the rest of the body. It is not a fibrous protein. D) Collagen is a fibrous protein that is the main component of connective tissues such as tendons, ligaments, and skin. It provides strength and structure to these tissues.

3. Which vitamin deficiency can lead to kidney stones?

• A. Vitamin A
• B. Vitamin B12
• C. Vitamin D
• D. Vitamin K

Correct answer: D

Rationale: The correct answer is D, Vitamin K. Vitamin K plays a role in blood clotting and bone health. A deficiency in Vitamin K can lead to an increased risk of kidney stones due to the improper regulation of calcium in the body. Calcium can accumulate in the kidneys and form stones if not properly managed. Vitamin K deficiency can disrupt the balance of calcium in the body, contributing to the development of kidney stones. Therefore, it is important to ensure an adequate intake of Vitamin K to prevent kidney stone formation.

4. A car is traveling at a constant speed on a straight road. What is the net force acting on the car?

• A. A force equal to its weight pushing upwards
• B. A force equal to its weight pushing downwards
• C. A force equal to its engine power pushing forward
• D. No net force

Correct answer: D

Rationale: Since the car's speed is constant, there is no acceleration, and according to Newton's first law, a net force of zero is required.

5. What is the net ionic equation for the reaction: 2HCl(aq) + Ba(OH)2(aq) → 2H2O(l) + BaCl2(aq)?

• A. 2H+(aq) + 2OH-(aq) → 2H2O(l)
• B. 2HCl(aq) + Ba(OH)2(aq) → BaCl2(aq) + 2H2O(l)
• C. 2H+(aq) + Ba2+(aq) → Ba2+(aq) + 2H+(aq)
• D. Ba(OH)2(aq) + HCl(aq) → BaCl2(aq) + 2H2O(l)

Correct answer: a

Rationale: The net ionic equation includes only the species that undergo a change during the reaction.

6. What kind of lens focuses parallel light rays to a single point?

• A. Concave lens
• B. Convex lens
• C. Cylindrical lens
• D. Plano lens

Correct answer: B

Rationale: Convex lenses (converging lenses) bend incoming light rays inwards, focusing them to a point called the focal point.

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