Nursing Elites

1. Autoimmune diseases occur when the immune system mistakenly attacks healthy body tissues. What is a potential cause of autoimmune diseases?

• A. Deficiency in essential vitamins and minerals
• B. Exposure to environmental toxins
• C. Breakdown in immune cell self-tolerance mechanisms
• D. All of the above

Correct answer: C

Rationale: Autoimmune diseases result from a breakdown in immune cell self-tolerance mechanisms, leading to the immune system mistakenly attacking healthy body tissues. While deficiencies in essential vitamins and minerals or exposure to environmental toxins can impact overall health, they are not direct causes of autoimmune diseases. Deficiency in essential vitamins and minerals may weaken the immune system, making it more susceptible to various health issues but does not directly cause autoimmune diseases. Exposure to environmental toxins can trigger immune responses, but autoimmune diseases specifically stem from the breakdown of self-tolerance mechanisms within immune cells. Therefore, the correct answer is a breakdown in immune cell self-tolerance mechanisms.

2. Balance the chemical equation: C4H10 + O2 → CO2 + H2O. What is the coefficient for oxygen?

• A. 5
• B. 6
• C. 7
• D. 8

Correct answer: B

Rationale: To balance the chemical equation, we need to ensure that the number of each type of atom is the same on both sides of the equation. In this case, there are 10 oxygen atoms on the right side (5 in CO2 and 5 in H2O). To balance this, we need to add a coefficient of 6 in front of O2 on the left side, resulting in 6 O2 molecules. This change will give us a total of 12 oxygen atoms on both sides, making the equation balanced. Choice A (5) is incorrect because it does not account for all the oxygen atoms present in the products. Choices C (7) and D (8) are incorrect as they would result in an imbalance in the number of oxygen atoms on both sides of the equation.

3. How does the mass of an object affect its inertia?

• A. Mass has no impact on inertia
• B. Higher mass increases inertia
• C. Higher mass decreases inertia
• D. Mass influences gravitational force, not inertia

Correct answer: B

Rationale: Inertia is the resistance of an object to changes in its state of motion. The greater the mass of an object, the greater its inertia because it requires more force to change its state of motion. This concept aligns with Newton's first law of motion, which states that an object at rest will remain at rest, and an object in motion will continue in motion with the same speed and direction unless acted upon by an external force. Therefore, higher mass increases inertia, making it more difficult to alter the object's state of motion. Choice A is incorrect as mass does impact inertia. Choice C is incorrect as higher mass actually increases inertia, not decreases it. Choice D is incorrect as while mass does affect gravitational force, it also directly impacts inertia.

4. A patient's body is not properly filtering blood. Which of the following body parts is most likely malfunctioning?

• A. Medulla
• B. Heart
• C. Nephrons
• D. Renal cortex

Correct answer: C

Rationale: Nephrons are the functional units of the kidneys responsible for filtering blood and removing waste products to form urine. If a patient's body is not properly filtering blood, it is most likely due to dysfunction or impairment in the nephrons of the kidneys. The heart is responsible for pumping blood, not filtering it, making choice B incorrect. The medulla and renal cortex are specific parts of the kidney but do not directly perform the filtration function carried out by the nephrons, making choices A and D incorrect.

5. What phenomenon explains the formation of rainbows in the sky?

• A. Diffraction
• B. Interference
• C. Refraction and dispersion of sunlight by water droplets
• D. Reflection from clouds

Correct answer: C

Rationale: Rainbows are formed due to the refraction and dispersion of sunlight by water droplets in the atmosphere. When sunlight enters a water droplet, it is refracted, then internally reflected, and finally refracted again as it exits the droplet. This dispersion of light into its component colors creates the beautiful rainbow we see in the sky. Choice A, diffraction, involves bending of light around obstacles or through narrow openings, not the splitting of light into colors as seen in rainbows. Choice B, interference, refers to the phenomenon where two or more light waves overlap and interact, producing a pattern of light and dark bands, which is not the case with rainbows. Choice D, reflection from clouds, does not accurately describe the process involved in the formation of rainbows through refraction and dispersion of light by water droplets.

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