Nursing Elites

1. What is the formula for calculating molarity?

• A. M = n/V
• B. M = n/L
• C. M = mol/L
• D. M = mol/dm³

Correct answer: a

Rationale: All of these choices are equivalent to the original formula. The symbol "n" represents the number of moles of solute, and the symbol "V" represents the volume of the solution in liters. The symbol "L" is an abbreviation for "liters," and "dm³" is an alternative way to represent liters.

2. The gradual loss of topsoil due to wind or water erosion is called:

• A. Desertification
• B. Leaching
• C. Salinization
• D. Acidification

Correct answer: A

Rationale: Rationale: A) Desertification refers to the process by which fertile land becomes desert, typically as a result of drought, deforestation, or inappropriate agriculture practices. The gradual loss of topsoil due to wind or water erosion can lead to the degradation of land and contribute to desertification. B) Leaching is the process by which minerals are washed out of the soil by water moving downwards through it. C) Salinization occurs when salt accumulates in the soil, usually as a result of irrigation in arid regions. D) Acidification refers to the decrease in soil pH, often caused by acid rain or the use of acidic fertilizers.

3. Why are isotopes of the same element chemically similar?

• A. They have the same number of protons.
• B. They have the same number of electrons.
• C. Their chemical properties are identical.
• D. They share the same electron configuration.

Correct answer: A

Rationale: They have the same number of protons. This determines the element's identity and its interactions with other elements, leading to similar chemical behavior, even if the number of neutrons differs.

4. Fingernails and toenails are made primarily of:

• A. Collagen (Collagen is found in the dermis)
• B. Keratin
• C. Melanin (Melanin provides pigment, not structure)
• D. Sebum (Sebum is an oily substance)

Correct answer: B

Rationale: The correct answer is B: Keratin. Fingernails and toenails are primarily made of a tough protein called keratin. Keratin is a fibrous structural protein that also makes up hair and the outer layer of skin. Collagen, as mentioned in option A, is found in the dermis of the skin and is responsible for providing strength and elasticity to the skin. Melanin, as in option C, is a pigment that gives color to the skin, hair, and eyes, but it does not contribute to the structure of nails. Sebum, as in option D, is an oily substance produced by the sebaceous glands in the skin to moisturize and protect the skin, but it is not a component of nails.

5. Tight junctions are specialized regions between animal cells that perform which function?

• A. Communication between cells
• B. Anchorage between cells
• C. Selective passage of materials
• D. All of the above

Correct answer: D

Rationale: The correct answer is D, 'All of the above.' Tight junctions are specialized structures between animal cells that serve multiple functions. They facilitate communication between cells by allowing signaling molecules to pass through. Additionally, tight junctions provide anchorage between cells, helping to maintain tissue structure and integrity. Moreover, tight junctions regulate the selective passage of materials across cell layers, acting as a barrier to prevent the free diffusion of substances. Therefore, all the functions mentioned in the options are performed by tight junctions, making 'All of the above' the correct choice.

6. Which vitamin plays a vital role in muscle function and helps prevent muscle weakness and fatigue?

• A. Vitamin A
• B. Vitamin B12
• C. Vitamin D
• D. Vitamin E

Correct answer: B

Rationale: The correct answer is B: Vitamin B12. Vitamin B12 plays a crucial role in muscle function by aiding in the production of red blood cells, which carry oxygen to the muscles. This vitamin also helps maintain the health of nerves that control muscle movements. Deficiency in vitamin B12 can lead to muscle weakness and fatigue due to decreased oxygen delivery and impaired nerve function in the muscles. Vitamin A is important for vision and immune function, Vitamin D is crucial for bone health, and Vitamin E is an antioxidant that protects cells from damage, but they do not have the same direct impact on muscle function as Vitamin B12.

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