Nursing Elites

1. What two factors enable some intercellular chemical signals to diffuse across cell membranes and bind to intracellular receptors?

• A. They are small and soluble.
• B. They are large and soluble.
• C. They are small and insoluble.
• D. They are large and insoluble.

Correct answer: A

Rationale: The correct answer is A: 'They are small and soluble.' Small and soluble molecules can easily pass through cell membranes and bind to intracellular receptors. Being small allows them to pass through the membrane, while being soluble enables them to dissolve in the aqueous environment inside the cell. Choice B is incorrect because large molecules typically cannot pass through the cell membrane easily. Choices C and D are incorrect because insoluble molecules would not dissolve in the aqueous environment inside the cell, hindering their ability to bind to intracellular receptors.

2. What is the definition of 'acceleration' in terms of motion?

• A. Change in velocity over time
• B. Speed in a straight line
• C. Distance covered in a given time
• D. Force applied to an object

Correct answer: A

Rationale: Acceleration is defined as the rate of change of velocity of an object over time. It represents how an object's velocity is changing, either by speeding up, slowing down, or changing direction. Option B, 'Speed in a straight line,' actually refers to velocity, not acceleration. Option C, 'Distance covered in a given time,' is more related to speed, as it measures how much ground is covered in a specific time period. Option D, 'Force applied to an object,' is not the definition of acceleration; it is a force exerted on an object that can cause acceleration.

3. Identify the spectator ions in the reaction: 2KCl + Pb(NO3)2 → 2KNO3 + PbCl2.

• A. K+ and NO3-
• B. K+ and Cl-
• C. Pb2+ and NO3-
• D. Pb2+ and Cl-

Correct answer: B

Rationale: - In the reaction, potassium ions (K+) and chloride ions (Cl-) are present on both sides of the equation. They are not involved in the formation of the products and remain unchanged. - Lead ions (Pb2+) and nitrate ions (NO3-) are involved in the formation of the products potassium nitrate (KNO3) and lead(II) chloride (PbCl2). - Therefore, the spectator ions in this reaction are K+ and Cl-.

4. Parkinson's disease is a neurodegenerative disorder affecting which neurotransmitter?

• A. Dopamine
• B. Acetylcholine
• C. Serotonin
• D. Glutamate

Correct answer: A

Rationale: Parkinson's disease is primarily caused by the loss of dopamine-producing neurons in the brain. Dopamine is a neurotransmitter that plays a crucial role in coordinating movement. The reduction of dopamine levels leads to the characteristic motor symptoms of Parkinson's disease, such as tremors, rigidity, and bradykinesia. Choice B, acetylcholine, is involved in functions like muscle contraction and autonomic nervous system regulation but is not primarily affected in Parkinson's disease. Serotonin (Choice C) is involved in mood regulation and sleep, not the main neurotransmitter affected in Parkinson's disease. Glutamate (Choice D) is the major excitatory neurotransmitter in the central nervous system and is not primarily implicated in Parkinson's disease pathophysiology.

5. A car is accelerating down a hill. Which of the following forces is NOT acting on the car?

• A. Gravitational force
• B. Normal force from the road
• C. Air resistance
• D. The car's engine force

Correct answer: B

Rationale: When a car is accelerating down a hill, the normal force from the road is not acting on the car. The normal force is the force exerted by a surface to support the weight of an object resting on it. As the car moves downhill, the normal force decreases since the road is no longer pushing back against the car's weight due to the downhill motion. Gravitational force pulls the car downhill, air resistance opposes the car's motion, and the car's engine force propels it forward. Therefore, the correct answer is B, as the normal force from the road is not acting on the car while it accelerates downhill.

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