Nursing Elites

1. How will mildly elevated levels of thyroxine affect the heart rate?

• A. Stop the heart rate
• B. No effect
• C. Decrease the heart rate
• D. Increase the heart rate

Correct answer: D

Rationale: Mildly elevated levels of thyroxine will increase the heart rate. Thyroxine, a hormone produced by the thyroid gland, regulates metabolism. Elevated thyroxine levels can lead to increased metabolism, resulting in an elevated heart rate. Choice A is incorrect as mildly elevated thyroxine levels do not stop the heart rate. Choice B is incorrect because elevated thyroxine levels do have an effect on heart rate. Choice C is incorrect as elevated thyroxine levels typically lead to an increase rather than a decrease in heart rate.

2. Which of the following is a component of the immune system?

• A. Red blood cells
• B. White blood cells
• C. Platelets
• D. Plasma

Correct answer: B

Rationale: White blood cells are a crucial component of the immune system as they play a key role in fighting infections and foreign invaders. Red blood cells are primarily involved in oxygen transport, platelets are important for blood clotting, and plasma is the liquid component of blood that carries various substances but is not directly involved in the immune response.

3. What is the acceleration of an object moving at a constant speed of 20 m/s if it comes to a complete stop within 5 seconds?

• A. 0 m/s² (no acceleration)
• B. 4 m/s²
• C. -4 m/s²
• D. Insufficient information

Correct answer: C

Rationale: To find the acceleration, we use the formula: acceleration = (final velocity - initial velocity) / time. Given that the final velocity is 0 m/s (as the object stops), the initial velocity is 20 m/s, and the time taken is 5 seconds. Substituting these values into the formula, we get acceleration = (0 m/s - 20 m/s) / 5 s = -20 m/s / 5 s = -4 m/s². Therefore, the acceleration is -4 m/s², indicating that the object decelerated at a rate of 4 m/s² to come to a complete stop. Choice A is incorrect because the object does experience acceleration as it changes its speed from 20 m/s to 0 m/s. Choice B is incorrect as it represents acceleration in the wrong direction, considering the object is decelerating. Choice D is incorrect as there is sufficient information provided to calculate the acceleration based on the given data.

4. What is the largest lymphatic vessel in the body?

• A. Jugular vein
• B. Thoracic duct
• C. Subclavian vein
• D. Aorta

Correct answer: B

Rationale: The thoracic duct is the largest lymphatic vessel in the body, responsible for draining lymph from most parts of the body except for the right upper quadrant. The jugular vein, subclavian vein, and aorta are not part of the lymphatic system; they are blood vessels and do not serve as lymphatic vessels. Therefore, choices A, C, and D are incorrect as they are not associated with the lymphatic system's transport of lymph.

5. When ethanol (C₂H₅OH) reacts with sodium metal (Na), what is the product?

• A. Ethene (C₂H₄)
• B. Sodium ethoxide (C₂H₅ONa)
• C. Ethane (C₂H₆)
• D. Sodium acetate (CH₃COONa)

Correct answer: B

Rationale: When ethanol (C₂H₅OH) reacts with sodium metal (Na), the product formed is Sodium ethoxide (C₂H₅ONa). This reaction is a classic example of a metal displacing hydrogen in an alcohol to form an alkoxide. In this specific case, sodium replaces the hydrogen in ethanol, resulting in the formation of sodium ethoxide. Choice A, Ethene (C₂H₄), is incorrect as it is a different compound formed from the dehydration of ethanol, not its reaction with sodium. Choice C, Ethane (C₂H₆), is incorrect as it is a saturated hydrocarbon, not the product of the reaction of ethanol with sodium metal. Choice D, Sodium acetate (CH₃COONa), is incorrect as it involves acetic acid, not ethanol, reacting with sodium to form the salt sodium acetate.

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