Nursing Elites

1. A car is moving in a circle at a constant speed. Which of the following is NOT true about its motion?

• A. It has a constant centripetal acceleration
• B. Its tangential velocity remains constant
• C. It experiences a force directed towards the center of the circle
• D. It covers the same distance in equal time intervals along its circular path

Correct answer: B

Rationale: In circular motion at a constant speed, the car has a constant centripetal acceleration (choice A), experiences a force directed towards the center of the circle (choice C), and covers the same distance in equal time intervals along its circular path (choice D). However, the tangential velocity of an object in circular motion at a constant speed changes continuously as it moves around the circle, so it is not constant (choice B). The change in tangential velocity allows the car to maintain its motion in a circular path despite moving at a constant speed. Choice A is incorrect because centripetal acceleration is indeed present to keep the car moving in a circular path. Choice C is incorrect as a force towards the center is required to keep the car in circular motion. Choice D is incorrect because the car covers equal distances in equal time intervals to maintain its circular trajectory.

2. Sebaceous glands, located in the dermis, secrete an oily substance called:

• A. Sweat
• B. Sebum
• C. Cerumen
• D. Mucus

Correct answer: B

Rationale: Sebaceous glands are responsible for secreting an oily substance called sebum, not sweat, cerumen, or mucus. Sebum plays a vital role in lubricating and waterproofing the skin and hair, preventing them from drying out. Sweat glands produce sweat to regulate body temperature. Cerumen is the medical term for earwax, produced by ceruminous glands in the ear canal, while mucus is a slimy substance that protects and lubricates body tissues. Therefore, the correct answer is B: Sebum, as it is the oily substance secreted by sebaceous glands.

3. What is the definition of power in physics?

• A. The rate of change of energy
• B. The rate of doing work or transferring energy
• C. The measure of an object's potential energy
• D. The force exerted on an object

Correct answer: B

Rationale: The correct answer is B: 'The rate of doing work or transferring energy.' Power in physics is defined as the rate at which work is done or energy is transferred. It is a measure of how quickly energy is transferred or converted. Power is not the same as energy itself but rather how fast energy is being transferred or converted. Choice A, 'The rate of change of energy,' is incorrect because power is about the rate of work or energy transfer, not just the change in energy. Choice C, 'The measure of an object's potential energy,' is incorrect as power is not a measure of potential energy but rather the rate of energy transfer. Choice D, 'The force exerted on an object,' is incorrect as power is related to work and energy transfer, not just force exerted.

4. Which part of the neuron is responsible for transmitting signals away from the cell body and toward other neurons or muscles?

• A. Axon
• B. Dendrite
• C. Synapse
• D. Myelin sheath

Correct answer: A

Rationale: The axon is the part of the neuron responsible for transmitting signals away from the cell body and toward other neurons or muscles. It is a long, slender projection covered by the myelin sheath, which speeds up signal transmission. Dendrites, on the other hand, receive signals from other neurons and transmit them toward the cell body. The synapse is the junction between two neurons where communication occurs, but it is not responsible for transmitting signals away from the cell body.

5. Which technology allows scientists to directly edit the human genome?

• A. Polymerase Chain Reaction (PCR)
• B. Gel electrophoresis
• C. DNA sequencing
• D. CRISPR-Cas9

Correct answer: D

Rationale: CRISPR-Cas9 is the correct answer. A) Polymerase Chain Reaction (PCR) is used for amplifying specific DNA segments, not directly editing the human genome. B) Gel electrophoresis is for separating DNA fragments by size, not for genome editing. C) DNA sequencing determines DNA nucleotide order but does not directly edit the genome. D) CRISPR-Cas9 technology enables precise modifications in the DNA of organisms, including humans. It guides the Cas9 enzyme to specific genome locations for targeted edits, revolutionizing genetic research and offering various applications in gene editing and therapy. Unlike the other techniques mentioned, CRISPR-Cas9 is specifically designed to make changes in the genetic code itself, making it a powerful tool for genetic manipulation.

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