Nursing Elites

1. Which vitamin is essential for calcium absorption and bone health?

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

Correct answer: C

Rationale: Vitamin D is essential for calcium absorption in the intestines, which is crucial for maintaining strong and healthy bones. Without adequate vitamin D, the body cannot effectively absorb calcium, leading to weakened bones and an increased risk of fractures. Vitamin A (Choice A) is important for vision and immune function but is not directly involved in calcium absorption or bone health. Vitamin C (Choice B) is essential for collagen synthesis and immune function, but it does not play a direct role in calcium absorption or bone health. Vitamin E (Choice D) acts as an antioxidant and helps protect cells from damage, but it is not specifically required for calcium absorption or bone health. Therefore, the correct answer is Vitamin D as it is crucial for optimal bone health.

2. Which of the following choices would contain the code for making a protein?

• A. mRNA
• B. tRNA
• C. rRNA
• D. DNA polymerase

Correct answer: A

Rationale: The correct answer is A: mRNA (messenger RNA). mRNA contains the genetic code or instructions for making a protein. During protein synthesis, mRNA carries the genetic information from DNA in the cell nucleus to the ribosomes, where proteins are synthesized. The sequence of nucleotides in mRNA corresponds to the sequence of amino acids that will be used to build the protein. Choice B, tRNA (transfer RNA), is involved in carrying amino acids to the ribosome during protein synthesis but does not contain the code for making a protein. Choice C, rRNA (ribosomal RNA), is a component of ribosomes where protein synthesis occurs but does not contain the specific code for making a protein. Choice D, DNA polymerase, is an enzyme involved in DNA replication, not in directly coding for protein synthesis.

3. What information can be obtained from the mass number of an element?

• A. The number of protons in the nucleus
• B. The total number of protons and neutrons
• C. The number of electrons in the valence shell
• D. The element's chemical reactivity

Correct answer: B

Rationale: The mass number of an element represents the total number of protons and neutrons in the nucleus. This information is crucial for determining the atomic mass of the element and understanding its stability and isotopes. The number of protons in the nucleus (option A) is represented by the atomic number, not the mass number. The number of electrons in the valence shell (option C) is related to the element's position in the periodic table and its chemical properties, but it is not directly determined by the mass number. The element's chemical reactivity (option D) is influenced by the number and arrangement of electrons in the atom's energy levels, not by the mass number.

4. What is the function of the sinuses?

• A. To trap many airborne pathogens
• B. To direct air down the trachea rather than the esophagus
• C. To warm, humidify, and filter air
• D. To sweep away pathogens and direct them toward the top of the trachea

Correct answer: C

Rationale: The correct function of the sinuses is to warm, humidify, and filter the air we breathe. Sinuses play a crucial role in preparing the air for the respiratory system by adding moisture, warmth, and filtering out particles. Choice A is incorrect because while sinuses can help filter some particles, their primary function is not to trap pathogens. Choice B is incorrect as the sinuses do not control the direction of air down the trachea; this is regulated by the epiglottis and vocal cords. Choice D is incorrect as sinuses do not sweep pathogens away or direct them towards the trachea; instead, they condition the air for respiration.

5. How do isotopes affect the atomic mass of an element?

• A. Isotopes have no effect on the atomic mass of an element.
• B. Isotopes cause the atomic mass of an element to vary slightly.
• C. Isotopes cause the atomic mass of an element to be exactly the same for all isotopes of that element.
• D. Isotopes cause the atomic mass of an element to vary greatly.

Correct answer: B

Rationale: Isotopes are atoms of the same element that have the same number of protons but different numbers of neutrons. Since the atomic mass of an element is the weighted average of the masses of its isotopes, the presence of isotopes causes the atomic mass of an element to vary slightly. This variation occurs because different isotopes have different masses due to their varying numbers of neutrons. The atomic mass is affected by the abundance of each isotope, leading to a slight fluctuation in the overall atomic mass of the element. Choice A is incorrect because isotopes do influence the atomic mass. Choice C is incorrect because isotopes have different masses, affecting the overall atomic mass. Choice D is incorrect as isotopes typically do not cause a significant variation in atomic mass, but rather a slight fluctuation.

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