Nursing Elites

1. What is the composition of the plasma membrane?

• A. Proteins
• B. Lipids
• C. Carbohydrates
• D. Nucleotides

Correct answer: B

Rationale: The plasma membrane is composed of lipids, proteins, and carbohydrates. While proteins are an essential component of the plasma membrane, it is not the only constituent. Carbohydrates and lipids also play crucial roles in the structure and function of the plasma membrane. Nucleotides are not part of the primary structural components of the plasma membrane, making this choice incorrect.

2. What happens to messenger RNA when it reaches the cytoplasm?

• A. It attaches to a ribosome.
• B. It unzips, exposing nitrogen bases.
• C. It pairs with the DNA bases.
• D. It pulls free of the DNA strand.

Correct answer: A

Rationale: Messenger RNA (mRNA) carries genetic information from the DNA in the nucleus to the ribosomes in the cytoplasm. When mRNA reaches the cytoplasm, it attaches to a ribosome. The ribosome functions as the site for protein synthesis through translation, where the genetic code carried by mRNA is read and translated into a specific sequence of amino acids. Choices B, C, and D are incorrect because mRNA does not unzip, expose nitrogen bases, pair with DNA bases, or pull free of the DNA strand in the cytoplasm. The primary function of mRNA in the cytoplasm is to serve as a template for protein synthesis by binding to ribosomes.

3. Tonicity refers to the movement of:

• A. Water
• B. Solute
• C. Cells
• D. None of the above

Correct answer: A

Rationale: Tonicity refers to the movement of water across a membrane in response to differences in solute concentration. In a hypertonic solution, where there is a higher concentration of solutes outside the cell, water will move out of the cell to try to reach equilibrium. In a hypotonic solution, where there is a lower concentration of solutes outside the cell, water will move into the cell to balance the concentrations. Cells and solutes themselves do not actively move in response to tonicity; it is the movement of water that helps achieve equilibrium. Therefore, the correct answer is water (Choice A). Choices B, C, and D are incorrect as tonicity specifically refers to water movement and not the movement of solutes, cells, or none of the above.

4. What provides the cell with the ability to move and propel?

• A. Microfilaments
• B. Microtubules
• C. Flagella
• D. Cilia

Correct answer: B

Rationale: Microtubules are the cellular structures responsible for cell movement and propulsion. Microtubules are part of the cytoskeleton and play a crucial role in various cellular processes, including cell motility and intracellular transport. While microfilaments also contribute to cell movement by enabling muscle contraction and cell shape changes, they are not primarily responsible for propelling the cell. Flagella and cilia are cellular appendages involved in cell movement, but they are composed of microtubules, making them the structures that move due to the actions of microtubules.

5. What is the fundamental unit of life?

• A. Atom
• B. Cell
• C. Tissue
• D. Organ

Correct answer: B

Rationale: The correct answer is 'B: Cell.' Cells are indeed the fundamental unit of life as they are responsible for all living functions, including growth, reproduction, and maintaining homeostasis. While atoms are the basic building blocks of matter, cells are the smallest structural and functional unit of living organisms. Choices C and D, tissue and organ respectively, are composed of multiple cells working together and are not considered the basic unit of life.

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