Nursing Elites

1. 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.

2. Why does cellular respiration happen?

• A. Cells can copy DNA
• B. Cells can breathe
• C. Cells can convert nutrients to energy
• D. Cells can divide

Correct answer: C

Rationale: Cellular respiration is the process through which cells break down nutrients such as glucose to produce ATP (adenosine triphosphate), the energy currency of the cell. This process allows cells to extract energy from food molecules and use it for various cellular activities and functions. Choices A, B, and D are incorrect because cellular respiration is specifically about converting nutrients to energy, not about DNA copying, breathing, or cell division.

3. Which names a final step in protein synthesis?

• A. DNA unzips.
• B. Amino acids bond.
• C. Transfer RNA bonds to messenger RNA.
• D. Messenger RNA moves to ribosomes.

Correct answer: B

Rationale: The final step in protein synthesis is when amino acids bond together to form a protein chain. This process occurs during translation, where transfer RNA (tRNA) brings specific amino acids to the ribosome, and the ribosome catalyzes the formation of peptide bonds between the amino acids. This step ultimately leads to the synthesis of a complete protein based on the instructions from messenger RNA (mRNA). Choice A ('DNA unzips') is incorrect as it refers to the initiation of transcription, not the final step of protein synthesis. Choice C ('Transfer RNA bonds to messenger RNA') is incorrect as it describes the process of translation initiation rather than the final step. Choice D ('Messenger RNA moves to ribosomes') is also incorrect as mRNA is already present at the ribosomes throughout the translation process, not just in the final step.

4. DNA bases include all but which of the following?

• A. Adenine
• B. Thymine
• C. Uracil
• D. Cytosine

Correct answer: C

Rationale: The correct answer is C: Uracil. Uracil is not a DNA base; it is a base found only in RNA. The four bases in DNA are Adenine, Thymine, Cytosine, and Guanine. Choice A, Adenine, is a correct DNA base. Choice B, Thymine, is a correct DNA base. Choice D, Cytosine, is a correct DNA base. Therefore, Uracil is the only incorrect choice among the options provided.

5. Epithelial cells are:

• A. Polarized
• B. Neutral
• C. Larger than other cells
• D. None of the above

Correct answer: A

Rationale: Epithelial cells have a distinct top (apical) and bottom (basal) side, demonstrating polarity. This polarity is essential for their specialized functions, such as secretion, absorption, and barrier formation. Choice B, 'Neutral,' is incorrect as epithelial cells exhibit polarity. Choice C, 'Larger than other cells,' is incorrect as epithelial cells come in various sizes and are not specifically larger than other cell types. Choice D, 'None of the above,' is incorrect as epithelial cells are indeed polarized.

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