Nursing Elites

1. What generates action potentials, the all-or-nothing electrical signals traveling along neurons?

• A. Glucose
• B. Sodium and potassium ions
• C. Neurotransmitters
• D. Myelin

Correct answer: B

Rationale: Action potentials, the all-or-nothing electrical signals traveling along neurons, are generated by the movement of sodium and potassium ions across the neuronal membrane. This movement creates changes in the membrane potential, leading to the propagation of the electrical signal along the neuron. Glucose is a source of energy for neurons but is not directly involved in generating action potentials. Neurotransmitters are involved in communication between neurons but do not directly generate action potentials. Myelin is a fatty substance that insulates and speeds up the conduction of action potentials but does not generate them.

2. What is the primary function of platelets in the blood?

• A. To carry oxygen
• B. To clot blood
• C. To fight infection
• D. To transport nutrients

Correct answer: B

Rationale: The correct answer is B: 'To clot blood.' Platelets play a crucial role in the clotting process, forming a plug at the site of blood vessel injury to prevent excessive bleeding. While red blood cells carry oxygen, white blood cells fight infection, and nutrients are transported by plasma, platelets are specifically responsible for blood clotting. Choice A is incorrect because red blood cells are responsible for carrying oxygen. Choice C is incorrect because white blood cells are primarily involved in fighting infection. Choice D is incorrect as the transport of nutrients is mainly carried out by plasma, not platelets.

3. What happens to the momentum of an object when there is no external force acting upon it?

• A. Momentum increases
• B. Momentum decreases
• C. Momentum remains constant
• D. Momentum becomes zero

Correct answer: C

Rationale: When there is no external force acting upon an object, the law of conservation of momentum dictates that the momentum of the object remains constant. This means that the momentum does not increase or decrease; it stays the same. Choice A is incorrect because momentum does not increase. Choice B is incorrect because momentum does not decrease. Choice D is incorrect as momentum does not become zero; it remains constant as per the conservation law. Therefore, the correct answer is C, as the object's momentum is unchanged in the absence of external forces.

4. Which of the following reagents can be used to convert a primary alcohol to an alkyl halide?

• A. HI
• B. H2O
• C. NaOH
• D. SOCl2

Correct answer: D

Rationale: SOCl2 (thionyl chloride) is commonly used to convert primary alcohols to alkyl halides through an SN2 mechanism. Thionyl chloride reacts with the alcohol to form an alkyl chloride. HI (hydroiodic acid) is typically used to convert alcohols to alkyl iodides specifically, not alkyl halides in general. H2O (water) and NaOH (sodium hydroxide) are not reagents used for converting alcohols to alkyl halides. Therefore, the correct answer is SOCl2 as it facilitates the conversion of primary alcohols to alkyl halides, unlike the other options provided.

5. Which type of joint allows for the widest range of motion, similar to the shoulder joint?

• A. Hinge joint
• B. Ball-and-socket joint
• C. Gliding joint
• D. Fixed joint

Correct answer: B

Rationale: The correct answer is B: Ball-and-socket joint. Ball-and-socket joints, like the shoulder joint, allow for the widest range of motion in multiple directions. This type of joint consists of a rounded bone (the 'ball') fitting into a cup-like socket, enabling movements such as flexion, extension, abduction, adduction, and rotation. Choice A, Hinge joint, allows movement in one plane, like a door hinge, and does not offer the same range of motion as a ball-and-socket joint. Choice C, Gliding joint, permits limited motion in various directions but not as wide as a ball-and-socket joint. Choice D, Fixed joint, does not allow any motion as it is immovable, unlike the shoulder joint which is highly mobile.

Similar Questions