Nursing Elites

1. What is the SI unit of measurement for acceleration?

• A. Meters per second (m/s)
• B. Newton (N)
• C. Meters (m)
• D. Meters per second squared (m/s²)

Correct answer: D

Rationale: The SI unit of measurement for acceleration is meters per second squared (m/s²). Acceleration is defined as the rate of change of velocity over time. It is a vector quantity with dimensions of length per time squared. Meters per second squared (m/s²) represents the change in velocity (meters per second) over a specific time interval (seconds) squared. Choice A, meters per second (m/s), represents velocity, not acceleration. Choice B, Newton (N), is the unit of force. Choice C, Meters (m), represents only distance, not acceleration. Therefore, the correct unit for acceleration is meters per second squared (m/s²).

2. What is the rigid structure that provides shape and support to plant cells?

• A. Cell wall
• B. Plasma membrane
• C. Nucleus
• D. Cytoplasm

Correct answer: A

Rationale: The correct answer is the cell wall, as it is the rigid structure that provides shape and support to plant cells. The cell wall is located outside the plasma membrane and is primarily composed of cellulose, giving it its rigid nature. The plasma membrane (option B) is a semi-permeable membrane surrounding the cell that regulates the movement of substances in and out of the cell. The nucleus (option C) houses the cell's genetic material and controls cellular activities. Cytoplasm (option D) is the gel-like substance within the cell that surrounds organelles and where various cellular processes take place, but it does not provide the rigid structure and support that the cell wall does.

3. Which level of protein structure is defined by the folds and coils of the protein's polypeptide backbone?

• A. Primary
• B. Secondary
• C. Tertiary
• D. Quaternary

Correct answer: B

Rationale: The correct answer is B: Secondary. The secondary structure of a protein is defined by the folds and coils of the protein's polypeptide backbone. This level of structure is characterized by the formation of alpha helices and beta sheets, which are stabilized by hydrogen bonds between amino acids along the polypeptide chain. Choice A, Primary, refers to the linear sequence of amino acids in the protein. Choice C, Tertiary, involves the 3D folding of the entire polypeptide chain. Choice D, Quaternary, pertains to the arrangement of multiple polypeptide subunits in a protein complex.

4. Vacuoles are large sacs for storage in plant cells. What is their main function in animal cells?

• A. Protein synthesis
• B. Waste storage and disposal
• C. Photosynthesis
• D. Cellular respiration

Correct answer: B

Rationale: Vacuoles in animal cells primarily function in waste storage and disposal, helping to maintain cellular homeostasis by storing waste products and aiding in their removal from the cell. Unlike plant cells, animal cells do not typically use vacuoles for storage purposes such as water, nutrients, or pigments. Instead, animal cells rely on other organelles like lysosomes for waste management and maintaining cellular balance. Choices A, C, and D are incorrect because protein synthesis occurs in ribosomes, photosynthesis takes place in chloroplasts (absent in animal cells), and cellular respiration mainly occurs in mitochondria, respectively. Vacuoles in animal cells serve a different purpose compared to plant cells.

5. Which structure allows for the selective passage of materials into and out of the cell?

• A. DNA
• B. Protein
• C. Carbohydrate
• D. Phospholipid bilayer

Correct answer: D

Rationale: The phospholipid bilayer is a crucial component of the cell membrane, surrounding the cell and regulating the passage of materials into and out of the cell. Its structure enables it to be selectively permeable, controlling which substances can pass through. DNA, proteins, and carbohydrates are essential molecules in the cell but do not directly govern the passage of materials like the phospholipid bilayer does. Therefore, the correct answer is the phospholipid bilayer.

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