Nursing Elites

1. Which of the following is not a biological macromolecule?

• A. Glycoproteins
• B. DNA
• C. Phospholipid
• D. Glucose

Correct answer: D

Rationale: Glucose is a monosaccharide, which is a simple sugar and not a macromolecule. Glycoproteins, DNA, and phospholipids are all examples of biological macromolecules. Glycoproteins are proteins covalently bonded to carbohydrates, DNA is a nucleic acid, and phospholipids are lipids that contain a phosphate group.

2. What is the length of DNA that can code for a particular protein?

• A. Chromosome
• B. Nucleotide
• C. Gene
• D. Ribosome

Correct answer: C

Rationale: The correct answer is C: Gene. A gene is a specific segment of DNA that contains the information necessary to produce a particular protein. Genes are responsible for coding proteins, and each gene carries the instructions for a specific protein. Chromosomes consist of many genes and are not a specific length that codes for a protein. Nucleotides are the building blocks of DNA and are not a length that codes for a protein. Ribosomes are cellular organelles involved in protein synthesis and do not directly code for proteins.

3. Which vitamin is crucial for calcium absorption and synthesized in the skin upon sun exposure?

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

Correct answer: C

Rationale: The correct answer is Vitamin D. Vitamin D is essential for calcium absorption as it helps regulate calcium and phosphorus levels in the body. When the skin is exposed to sunlight, UVB rays convert a compound in the skin to vitamin D. This vitamin is vital for maintaining bone health and ensuring the overall calcium balance in the body. Choices A, B, and D are incorrect. Vitamin A is important for vision and immune function, Vitamin C is essential for collagen synthesis and immune function, and Vitamin E is an antioxidant that helps protect cells from damage by free radicals. However, none of these vitamins are primarily responsible for calcium absorption and synthesized in the skin upon sun exposure.

4. Which of the following structures has the lowest blood pressure?

• A. Arteries
• B. Arterioles
• C. Venules
• D. Veins

Correct answer: D

Rationale: Veins have the lowest blood pressure among the listed structures. Blood pressure decreases as blood flows from arteries to arterioles, then to venules, and finally to veins. Veins return blood to the heart under low pressure because they have thinner walls and larger lumens compared to arteries and arterioles. This anatomical difference allows veins to accommodate a greater volume of blood without a significant rise in pressure. Arteries have the highest blood pressure to propel blood away from the heart, followed by arterioles which regulate blood flow to capillaries. Venules collect blood from capillaries and connect to veins, which then carry blood back to the heart at a lower pressure.

5. What is the balanced chemical equation for the reaction between sodium and chlorine to form sodium chloride?

• A. Na + Cl2 -> NaCl
• B. 2Na + Cl2 -> 2NaCl
• C. Na2 + Cl -> 2NaCl
• D. Na + 2Cl -> NaCl2

Correct answer: B

Rationale: In a balanced chemical equation, the number of atoms of each element must be the same on both sides of the equation. When sodium (Na) reacts with chlorine (Cl2) to form sodium chloride (NaCl), we need to ensure the equation is balanced. There are 2 chlorine atoms in Cl2; hence, we need 2 sodium atoms on the left side to balance it. Therefore, the balanced chemical equation is 2Na + Cl2 -> 2NaCl. Choice A is incorrect because it does not have the correct coefficients to balance the equation. Choice C is incorrect as it incorrectly represents the formula of sodium. Choice D is incorrect as it forms NaCl2, which is not the correct compound formed in this reaction.

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