Nursing Elites

1. 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.

2. T cells in the immune system can be categorized into different types. What type of T cell directly kills infected body cells?

• A. Helper T cells
• B. Cytotoxic T cells
• C. Regulatory T cells
• D. Memory T cells

Correct answer: B

Rationale: Cytotoxic T cells directly kill infected body cells by recognizing specific antigens on the surface of infected cells and releasing cytotoxic substances to induce cell death, eliminating the infected cells. Helper T cells assist in coordinating the immune response, regulatory T cells help maintain immune tolerance, and memory T cells mount a faster and stronger response upon re-exposure to a previously encountered antigen. Therefore, the correct answer is cytotoxic T cells as they play a crucial role in directly targeting and destroying infected cells.

3. How does the Law of Conservation of Mass apply to this reaction: 2H₂ + O₂ → 2H₂O?

• A. Electrons are not lost.
• B. The hydrogen does not lose mass.
• C. New water molecules are formed.
• D. There is no decrease or increase in matter.

Correct answer: D

Rationale: The Law of Conservation of Mass states that matter cannot be created or destroyed in a chemical reaction. In the given reaction, 2 moles of hydrogen combine with 1 mole of oxygen to form 2 moles of water. The total mass of the reactants (hydrogen and oxygen) is equal to the total mass of the products (water), meaning there is no decrease or increase in matter. The total mass of the system remains constant, demonstrating the conservation of mass. Choices A, B, and C are incorrect because the conservation of mass does not specifically relate to electrons, individual elements (like hydrogen), or the formation of new molecules; instead, it focuses on the overall mass of the system before and after the reaction.

4. What is a temporary loss of consciousness due to insufficient blood flow to the brain called?

• A. Stroke
• B. Seizure
• C. Syncope (fainting)
• D. Coma

Correct answer: C

Rationale: Syncope, also known as fainting, is a temporary loss of consciousness caused by insufficient blood flow to the brain. It results from a brief interruption in the brain's blood supply, leading to a temporary loss of consciousness. The correct answer is C. A stroke, option A, is caused by a blockage or rupture of blood vessels in the brain, not insufficient blood flow. Seizure, option B, involves a sudden surge of electrical brain activity, not reduced blood flow. Coma, option D, is characterized by prolonged unconsciousness, not a temporary loss of consciousness due to insufficient blood flow.

5. 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.

Similar Questions