Nursing Elites

1. In which units is the speed of light in a vacuum measured?

• A. Meters per second
• B. Hertz
• C. Candela
• D. Newton

Correct answer: A

Rationale: The speed of light in a vacuum is commonly measured in units of meters per second. This is because the speed of light is approximately 299,792,458 meters per second in a vacuum, as defined by the International System of Units (SI). The speed of light is a measure of distance covered by light in a given time, hence it is expressed in meters per second. Choices B, C, and D are incorrect. Hertz is a unit of frequency, Candela is a unit of luminous intensity, and Newton is a unit of force. None of these units are relevant for measuring the speed of light, making 'Meters per second' the correct unit of measurement for the speed of light.

2. What is the name for the hard, protective protein that makes up hair and nails?

• A. Collagen
• B. Keratin
• C. Elastin
• D. Fibrin

Correct answer: B

Rationale: Keratin is the correct answer as it is the hard, protective protein that comprises hair and nails. Collagen is a different type of protein found in connective tissues, providing structure and support. Elastin imparts elasticity to tissues, allowing them to stretch and recoil. Fibrin is a protein involved in the blood clotting process and is not related to the structure of hair and nails. Therefore, choices A, C, and D are incorrect in the context of the question.

3. What happens to the diaphragm during inspiration?

• A. It moves upward
• B. It moves downward
• C. It expands
• D. It contracts and moves downward

Correct answer: D

Rationale: During inspiration, the diaphragm contracts and moves downward. This action increases the volume of the thoracic cavity, which lowers the air pressure inside the lungs, allowing air to flow in. The downward movement and contraction of the diaphragm create the necessary space for the lungs to expand and fill with air. Choice A, 'It moves upward,' is incorrect as the diaphragm moves downward. Choice B, 'It moves downward,' is partially correct but misses the contraction aspect. Choice C, 'It expands,' is incorrect as the diaphragm itself does not expand during inspiration. Therefore, choice D, 'It contracts and moves downward,' is the most accurate description of the diaphragm's action during inspiration.

4. What is the energy required to break a chemical bond called?

• A. Kinetic energy
• B. Potential energy
• C. Activation energy
• D. Bond energy

Correct answer: C

Rationale: Activation energy is the energy required to break a chemical bond and initiate a chemical reaction. It is the minimum amount of energy needed to start a chemical reaction by breaking bonds in the reactant molecules. Kinetic energy (option A) is the energy of motion and is not directly related to breaking chemical bonds. Potential energy (option B) is stored energy that can be converted into other forms of energy but is not specifically about breaking chemical bonds. Bond energy (option D) refers to the energy required to break a particular chemical bond in a molecule and is not the general term for the energy needed to break any chemical bond. Activation energy is crucial in determining the rate of a chemical reaction as it affects the probability of reactant molecules colliding with sufficient energy to surpass the energy barrier and form products.

5. Which transport mechanism uses vesicles to move materials out of the cell?

• A. Endocytosis
• B. Active transport
• C. Diffusion
• D. Exocytosis

Correct answer: D

Rationale: Exocytosis is the transport mechanism that uses vesicles to move materials out of the cell. Vesicles carry substances to the cell membrane, fuse with it, and release their contents outside the cell. This process is essential for secreting molecules such as hormones, enzymes, or neurotransmitters. Endocytosis, on the other hand, is the process of bringing materials into the cell by engulfing them in vesicles. Active transport involves the movement of molecules across a cell membrane against their concentration gradient, requiring energy. Diffusion is the passive movement of molecules from an area of higher concentration to an area of lower concentration.

Similar Questions