Nursing Elites

1. What phenomenon explains the bending of light as it passes around an obstacle or through an aperture?

• A. Refraction
• B. Reflection
• C. Diffraction
• D. Dispersion

Correct answer: C

Rationale: Diffraction is the phenomenon that explains the bending of light as it passes around an obstacle or through an aperture. When light encounters an obstacle or passes through an aperture, it diffracts, causing it to bend around the edges. Refraction, on the other hand, occurs when light passes from one medium to another, causing it to change direction. Reflection involves the bouncing back of light rays from a surface, and dispersion is the separation of light into its different colors. Therefore, the correct answer is C, as diffraction specifically addresses the bending of light as it interacts with obstacles or apertures, unlike the other choices that describe different optical phenomena.

2. Osteoporosis is a condition that leads to weakened bones and an increased risk of fractures. Which hormone plays a key role in bone health and is often affected in osteoporosis?

• A. Estrogen
• B. Testosterone
• C. Thyroid hormone
• D. Insulin

Correct answer: A

Rationale: Estrogen plays a crucial role in maintaining bone health by inhibiting bone resorption and promoting bone formation. In postmenopausal women, estrogen levels decrease, leading to an increased risk of osteoporosis due to accelerated bone loss. This hormonal imbalance contributes to weakened bones and an increased risk of fractures in individuals with osteoporosis. Testosterone and thyroid hormone do play roles in bone health, but estrogen has a more significant impact. Testosterone is more commonly associated with muscle mass and strength, while thyroid hormone regulates metabolism. Insulin is not directly involved in bone health and is not typically affected in osteoporosis.

3. Which of the following accurately describes saltatory conduction?

• A. It is faster than normal nerve conduction
• B. It occurs from one node of Ranvier to the next
• C. It only occurs in myelinated neurons
• D. All of the above

Correct answer: D

Rationale: The correct answer is D, 'All of the above.' Saltatory conduction is faster than normal nerve conduction, occurs from one node of Ranvier to the next, and is exclusive to myelinated neurons. This form of conduction allows for the rapid transmission of nerve impulses by the action potential jumping between the nodes of Ranvier in myelinated neurons, enhancing the efficiency of signal propagation along the axon. Choice A is correct as saltatory conduction is indeed faster than normal conduction. Choice B is accurate as it describes the mechanism of conduction 'jumping' from one node of Ranvier to the next. Choice C is correct because saltatory conduction occurs specifically in myelinated neurons where the myelin sheath insulates the axon except at the nodes of Ranvier, facilitating faster transmission of nerve impulses.

4. Which lifestyle practice can weaken the immune system?

• A. Getting enough sleep
• B. Eating a balanced diet rich in fruits and vegetables
• C. Managing stress levels
• D. Frequent smoking

Correct answer: D

Rationale: Frequent smoking can weaken the immune system by damaging immune cells and impairing their function. Smoking increases the risk of respiratory infections and other illnesses, negatively impacting immune health. Therefore, frequent smoking is a lifestyle practice that can weaken the immune system. Choices A, B, and C are all beneficial practices that support a healthy immune system. Getting enough sleep, eating a balanced diet rich in fruits and vegetables, and managing stress levels are important for maintaining optimal immune function and overall well-being.

5. Which property of a substance refers to the force exerted on an object due to gravity?

• A. Mass
• B. Weight
• C. Density
• D. Volume

Correct answer: B

Rationale: The correct answer is 'Weight.' Weight is the force exerted on an object due to gravity. Mass, on the other hand, refers to the amount of matter in an object. Density is the mass per unit volume of a substance, and volume is the amount of space occupied by an object. In this context, weight specifically relates to the gravitational force acting on an object, making it the most appropriate choice among the options provided.

Similar Questions