Nursing Elites

1. Which of the following is an example of a polymer?

• A. Methane
• B. Ethanol
• C. Polyethylene
• D. Acetic acid

Correct answer: C

Rationale: The correct answer is C, Polyethylene. Polyethylene is a polymer composed of a large number of repeating ethylene units linked together, forming a long-chain molecule, characteristic of polymers. Methane, ethanol, and acetic acid are small organic molecules that do not demonstrate the repeating unit structure typical of polymers. Therefore, they are not examples of polymers.

2. What is the temperature of 35°C in Kelvin?

• A. 220
• B. 238
• C. 308
• D. 345

Correct answer: C

Rationale: To convert Celsius to Kelvin, add 273.15 to the Celsius temperature. In this case, 35°C + 273.15 = 308.15 K. Therefore, the correct answer is 308 K. Choice A (220) is incorrect as it does not account for adding 273.15 to convert to Kelvin. Choice B (238) is incorrect as it is not the result of adding 273.15 to 35°C. Choice D (345) is incorrect as it is not the correct conversion of 35°C to Kelvin.

3. What is the name of the strong acid produced by the stomach to help break down food?

• A. Hydrochloric acid
• B. Lactic acid
• C. Bile
• D. Fatty acid

Correct answer: A

Rationale: The correct answer is A, hydrochloric acid. The stomach produces hydrochloric acid to aid in the digestion process by breaking down food, particularly proteins. This acid is crucial for the proper absorption of nutrients in the stomach. Lactic acid is produced in muscles during intense exercise, not in the stomach. Bile is produced by the liver to assist in digestion, primarily in the small intestine, not in the stomach. Fatty acids are molecules found in fats with different functions in the body, but they are not the primary acid produced by the stomach for digestion.

4. What is the relationship between work and kinetic energy?

• A. Work is the cause of kinetic energy
• B. Kinetic energy is the result of work
• C. Work and kinetic energy are equivalent
• D. Work and kinetic energy are independent

Correct answer: A

Rationale: Work is defined as the transfer of energy that results in an object's displacement. When work is done on an object, it gains kinetic energy. This means that work is the cause of kinetic energy, as the energy transferred through work leads to the object's motion, which is represented by kinetic energy. Therefore, choice A is correct. Choice B is incorrect because kinetic energy is the result of work, not the other way around. Choice C is incorrect as work and kinetic energy are not equivalent but rather interconnected. Choice D is incorrect as work and kinetic energy are not independent; work leads to changes in kinetic energy.

5. What is the primary function of the myelin sheath that surrounds some axons in the nervous system?

• A. To initiate nerve impulses
• B. To transmit sensory information
• C. To speed up the transmission of nerve impulses
• D. To connect neurons at synapses

Correct answer: C

Rationale: The primary function of the myelin sheath is to speed up the transmission of nerve impulses. The myelin sheath acts as an insulating layer around the axon, allowing for faster conduction of electrical impulses along the nerve fiber. This insulation prevents the electrical signal from dissipating or 'leaking' out, which helps in the rapid and efficient transmission of nerve impulses along the axon. Choice A is incorrect because the myelin sheath does not initiate nerve impulses; it helps in conducting them. Choice B is incorrect as the myelin sheath's main role is not in transmitting sensory information but rather in facilitating the transmission of nerve impulses. Choice D is incorrect because the myelin sheath's function is not to connect neurons at synapses; instead, it is primarily involved in enhancing the speed of nerve impulse transmission.

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