Nursing Elites

1. Where is keratin found?

• A. It is a protein-digesting enzyme released by the stomach.
• B. It is released in the neuromuscular junction.
• C. It is a protein found in the hypodermis.
• D. It is a protein found in hair.

Correct answer: D

Rationale: Keratin is a structural protein found in hair, skin, and nails, providing strength and protection. It forms the main structural component of hair, making choice D the correct answer. Choices A, B, and C are incorrect because keratin is not an enzyme released by the stomach, not released in the neuromuscular junction, and not found in the hypodermis. Remember that keratin is primarily associated with structural support in epithelial cells.

2. Which of the following describes a scalar quantity?

• A. Velocity
• B. Acceleration
• C. Force
• D. Speed

Correct answer: D

Rationale: A scalar quantity is a physical quantity that has magnitude only, without any direction. Speed is an example of a scalar quantity because it only describes how fast an object is moving without specifying the direction of motion. Velocity, acceleration, and force are vector quantities because they have both magnitude and direction. Therefore, the correct answer is 'Speed.' Choices A, B, and C are incorrect because velocity, acceleration, and force are all vector quantities that involve both magnitude and direction.

3. When is a solution formed?

• A. One substance dissolves in another
• B. Two or more substances react chemically
• C. A solid changes to a liquid
• D. None of the above

Correct answer: A

Rationale: A solution is formed when one substance dissolves in another. This process creates a homogeneous mixture where the solute is dispersed in the solvent, resulting in a uniform composition throughout the mixture. Choice B is incorrect because chemical reactions involve the transformation of substances into new compounds, not the formation of solutions. Choice C is incorrect as it describes a physical change from a solid to a liquid, not the formation of a solution. Choice D is incorrect as one substance dissolving in another is the defining characteristic of a solution.

4. What is the process by which a cell divides into two or more new cells?

• A. Mitosis
• B. Meiosis
• C. Both mitosis and meiosis
• D. None of the above

Correct answer: A

Rationale: Mitosis is the process by which a cell divides into two identical daughter cells. This type of cell division is essential for growth, repair, and maintenance of multicellular organisms. Meiosis, on the other hand, is a type of cell division that produces gametes (sperm and egg cells) with half the number of chromosomes as the parent cell. Meiosis does not directly result in the formation of new cells, as it is specifically geared towards the production of reproductive cells. Therefore, the correct answer is A. Option C, stating both mitosis and meiosis, is incorrect because meiosis is not involved in the general process of cell division to produce new cells; it is specialized for gamete formation. Option D is incorrect because mitosis is indeed the process responsible for cell division in which one cell divides into two daughter cells, making it the accurate choice for this question.

5. What term describes the functional unit of a skeletal muscle responsible for muscle contraction?

• A. Myofibril
• B. Sarcomere
• C. Tendon
• D. Myoglobin

Correct answer: B

Rationale: The correct answer is B, 'Sarcomere.' The sarcomere is indeed the functional unit of a skeletal muscle responsible for muscle contraction. It is composed of actin and myosin filaments that interact to generate muscle contraction. Choice A, 'Myofibril,' is incorrect as myofibrils are composed of sarcomeres, not the functional units themselves. Choice C, 'Tendon,' is incorrect as tendons connect muscles to bones and do not directly participate in muscle contraction. Choice D, 'Myoglobin,' is incorrect as myoglobin is a protein that stores oxygen in muscle cells and is not directly involved in muscle contraction.

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