Nursing Elites

1. Two objects with different masses collide. What happens to their momentum after the collision?

• A. Increases for both objects
• B. Decreases for both objects
• C. Remains the same for both objects
• D. Can increase for one and decrease for the other

Correct answer: C

Rationale: In an isolated system (no external forces), the total momentum

2. The Hardy-Weinberg equilibrium describes a population that is:

• A. Undergoing rapid evolution due to strong directional selection.
• B. Not evolving and at genetic equilibrium with stable allele frequencies.
• C. Experiencing a founder effect leading to a reduction in genetic diversity.
• D. Dominated by a single homozygous genotype that eliminates all variation.

Correct answer: B

Rationale: Rationale: The Hardy-Weinberg equilibrium describes a theoretical population in which allele frequencies remain constant from generation to generation, indicating that the population is not evolving. This equilibrium occurs under specific conditions: no mutation, no gene flow, random mating, a large population size, and no natural selection. In this scenario, all genotypes are in proportion to the allele frequencies, and genetic diversity is maintained. Options A, C, and D do not accurately describe a population in Hardy-Weinberg equilibrium. Option A suggests rapid evolution due to strong directional selection, which would disrupt the equilibrium. Option C mentions a founder effect, which can reduce genetic diversity but is not a characteristic of a population in Hardy-Weinberg equilibrium. Option D describes a population dominated by a single homozygous genotype, which also does not align with the genetic diversity seen in a population at Hardy-Weinberg equilibrium.

3. 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.

4. The main function of the nephrons is to:

• A. Store urine
• B. Filter blood and remove waste products
• C. Produce hormones
• D. Control blood pressure

Correct answer: B

Rationale: The correct answer is B: 'Filter blood and remove waste products.' Nephrons are the functional units of the kidneys responsible for filtering blood to remove waste products, excess ions, and water, while reabsorbing essential substances like glucose and amino acids. This process forms urine, which is stored in the bladder before being excreted. Options A, C, and D are incorrect because nephrons do not store urine, produce hormones, or directly control blood pressure; although the kidneys do play a role in long-term blood pressure regulation through mechanisms like the renin-angiotensin-aldosterone system.

5. The lymphatic system is a network of vessels and organs that plays a vital role in:

• A. Transporting oxygen and nutrients to cells
• B. Carrying waste products away from tissues
• C. Regulating body temperature
• D. Producing red blood cells

Correct answer: B

Rationale: The correct answer is B: Carrying waste products away from tissues. The lymphatic system is responsible for collecting excess fluid and waste products from tissues and returning them to the bloodstream for removal. This helps maintain fluid balance in the body and supports immune function by transporting white blood cells to fight infections. Options A, C, and D do not accurately describe the function of the lymphatic system. Transporting oxygen and nutrients to cells is primarily the role of the circulatory system, while regulating body temperature is controlled by the nervous system and producing red blood cells occurs in the bone marrow.

6. Which hormone stimulates the release of pancreatic enzymes and bile?

• A. Gastrin
• B. Insulin
• C. Cholecystokinin (CCK)
• D. Glucagon

Correct answer: C

Rationale: The correct answer is C: Cholecystokinin (CCK). Cholecystokinin is a hormone produced by the small intestine in response to the presence of food, especially fats and proteins. It stimulates the release of pancreatic enzymes from the pancreas and bile from the gallbladder to aid in digestion. Gastrin is a hormone that stimulates the release of gastric acid in the stomach. Insulin and glucagon are hormones involved in regulating blood sugar levels, not the release of pancreatic enzymes and bile. Therefore, CCK is the hormone responsible for stimulating the release of pancreatic enzymes and bile in the digestive process.

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