Nursing Elites

1. What phenomenon occurs when a wave encounters a change in medium causing a change in its speed and direction?

• A. Refraction
• B. Reflection
• C. Diffraction
• D. Interference

Correct answer: a

Rationale: Refraction happens when a wave changes its speed and direction due to encountering a change in medium.

2. Simple columnar epithelium lining the small intestine is crucial for:

• A. Movement
• B. Support
• C. Absorption
• D. Insulation

Correct answer: C

Rationale: The correct answer is C: Absorption. The simple columnar epithelium lining the small intestine is crucial for absorption due to its structure and function. It has microvilli that increase the surface area available for nutrient absorption. This epithelium also contains specialized cells like goblet cells that secrete mucus to protect the lining and aid in the movement of materials. Movement (choice A) is more related to muscle tissue rather than epithelial tissue. Support (choice B) is usually provided by connective tissue rather than epithelial tissue. Insulation (choice D) is not a function of the simple columnar epithelium in the small intestine.

3. How does RNA polymerase differ from DNA polymerase?

• A. Both enzymes are identical in function and structure.
• B. RNA polymerase does not require a primer to initiate RNA synthesis.
• C. RNA polymerase can synthesize both RNA and DNA.
• D. RNA polymerase can only synthesize RNA, unlike DNA polymerase.

Correct answer: B

Rationale: Rationale: A) This statement is incorrect. RNA polymerase and DNA polymerase are not identical in function and structure. They have different roles in the cell. B) This statement is correct. Unlike DNA polymerase, RNA polymerase does not require a primer to initiate RNA synthesis. RNA polymerase can start the synthesis of RNA de novo. C) This statement is incorrect. RNA polymerase is specialized for synthesizing RNA, not DNA. DNA polymerase is responsible for synthesizing DNA. D) This statement is correct. RNA polymerase can only synthesize RNA, while DNA polymerase is responsible for synthesizing DNA.

4. Endotoxins are toxic substances released by:

• A. Viruses
• B. Bacteria (gram-positive)
• C. Bacteria (gram-negative)
• D. Parasites

Correct answer: C

Rationale: Rationale: Endotoxins are toxic substances that are part of the outer membrane of the cell wall of gram-negative bacteria. These toxins are released when the bacteria are destroyed or during bacterial growth. Endotoxins can cause a variety of harmful effects in the host, including fever, inflammation, and septic shock. Viruses do not produce endotoxins, and gram-positive bacteria produce exotoxins rather than endotoxins. Parasites are not typically associated with the production of endotoxins.

5. The moon-shaped white structures at the base of fingernails are called:

• A. Lunulae
• B. Cuticle
• C. Hyponychium
• D. Matrix

Correct answer: A

Rationale: The correct answer is A, "Lunulae." The moon-shaped white structures at the base of fingernails are called lunulae. These are most visible on the thumb and are the visible part of the nail matrix. The lunulae appear white because the nail matrix underneath is not visible due to its thickness. Cuticle (B) refers to the thin layer of skin at the base of the nail, hyponychium (C) is the skin located under the free edge of the nail, and matrix (D) is the tissue at the base of the nail where growth occurs. Therefore, the correct term for the moon-shaped white structures is lunulae.

6. The energy absorbed during a chemical reaction is called:

• A. Kinetic energy
• B. Potential energy
• C. Heat energy
• D. Endothermic energy

Correct answer: D

Rationale: Endothermic means "inward heat," indicating energy is absorbed during the reaction.

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