Nursing Elites

1. In contrast with triglycerides, phospholipids are lacking one of which of the following components?

• A. Monosaccharide
• B. Glycerol
• C. Phosphates
• D. Fatty acid

Correct answer: B

Rationale: Phospholipids are structurally similar to triglycerides but lack one of the fatty acid chains that triglycerides possess. Triglycerides consist of three fatty acid chains attached to a glycerol molecule, while phospholipids have two fatty acid chains and a phosphate group attached to a glycerol backbone. Therefore, phospholipids are lacking the third fatty acid chain found in triglycerides. Choice A (Monosaccharide) is incorrect because neither triglycerides nor phospholipids contain monosaccharides in their structure. Choice C (Phosphates) is incorrect because phospholipids actually contain phosphates, unlike triglycerides. Choice D (Fatty acid) is incorrect as both triglycerides and phospholipids contain fatty acids, but the number of fatty acid chains differs between the two.

2. The cell membrane consists of a bilayer of phospholipids with proteins, cholesterol, and glycoproteins. What does this bilayer create?

• A. Impermeable
• B. Permeable
• C. Selectively permeable
• D. Selectively impermeable

Correct answer: C

Rationale: The correct answer is 'Selectively permeable.' The cell membrane's bilayer structure allows it to be selectively permeable, meaning it can control the passage of substances. This property enables the membrane to regulate the entry and exit of specific molecules, ions, and other substances. Choice A, 'Impermeable,' is incorrect as the cell membrane is not completely impermeable and does allow certain substances to pass through. Choice B, 'Permeable,' is also incorrect as it does not address the selective nature of the membrane. Choice D, 'Selectively impermeable,' is a contradictory term and does not accurately describe the cell membrane's function.

3. The apical side of an epithelial cell:

• A. Is exposed to fluid or air
• B. Is on the bottom side of the cell
• C. Does not allow any substances to pass through
• D. None of the above

Correct answer: A

Rationale: The apical side of an epithelial cell is the top side, which is typically exposed to fluids, air, or the inside of an organ. This side allows substances to pass through it, facilitating the absorption, secretion, or excretion of various substances. Choice B is incorrect as the apical side is not on the bottom but the top side. Choice C is incorrect as the apical side does allow substances to pass through. Choice D is incorrect as there are characteristics associated with the apical side.

4. Which, if any, of the following statements are true?

• A. Water boils at approximately 100°C (212°F) at standard atmospheric pressure
• B. The boiling point is the temperature at which the vapor pressure is higher than the atmospheric pressure around the water
• C. Water boils at a lower temperature in areas of lower pressure
• D. A and C are true

Correct answer: D

Rationale: Both statements A and C are true. Water indeed boils at approximately 100°C (212°F) at standard atmospheric pressure. However, water boils at a lower temperature in areas of lower pressure due to the decreased atmospheric pressure, which affects the vapor pressure and boiling point of water. Statement B is incorrect because the boiling point is the temperature at which the vapor pressure equals the external pressure (atmospheric pressure in this case), not when it is higher.

5. From which component do RNA and DNA derive their names?

• A. From the sugar each contains
• B. From the structure of their nucleotides
• C. From the information they transfer
• D. From their formative processes

Correct answer: A

Rationale: RNA and DNA derive their names from the sugar each contains. RNA stands for Ribonucleic Acid, with 'ribo' indicating the ribose sugar in its structure. DNA stands for Deoxyribonucleic Acid, with 'deoxyribo' referring to the deoxyribose sugar in its structure. The sugars in RNA and DNA molecules distinguish them and are the basis for their names. Choices B, C, and D are incorrect as they do not accurately explain how RNA and DNA derive their names.

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