Nursing Elites

1. The body's first line of defense against pathogens is the innate immune system. Which of the following is NOT a component of the innate immune system?

• A. Physical barriers like skin and mucous membranes
• B. Phagocytes that engulf and destroy pathogens
• C. Inflammatory response to isolate and contain infection
• D. Production of antibodies specific to a particular pathogen

Correct answer: D

Rationale: The production of antibodies specific to a particular pathogen is a function of the adaptive immune system, not the innate immune system. The innate immune system provides immediate, non-specific defense mechanisms against pathogens, including physical barriers, phagocytes, and inflammatory responses. Choices A, B, and C are all correct components of the innate immune system. Physical barriers like skin and mucous membranes act as the first line of defense, preventing pathogens from entering the body. Phagocytes are specialized cells that engulf and destroy pathogens, while the inflammatory response helps isolate and contain infections to prevent their spread.

2. The resolution of an optical instrument, like a microscope, refers to its ability to distinguish between:

• A. Different colors of light
• B. The presence or absence of light
• C. Variations in intensity
• D. Very close, nearly identical objects

Correct answer: D

Rationale: The resolution of an optical instrument, such as a microscope, refers to its ability to distinguish between very close, nearly identical objects. This is crucial in microscopy to clearly visualize and differentiate fine details and structures. Resolving power plays a significant role in determining the quality and effectiveness of an optical instrument. Choices A, B, and C are incorrect because the resolution of an optical instrument does not primarily deal with different colors of light, presence or absence of light, or variations in intensity. Instead, it specifically focuses on the instrument's ability to differentiate between objects that are very close and nearly identical in nature.

3. Which force opposes the relative motion between surfaces in contact?

• A. Tension force
• B. Frictional force
• C. Gravitational force
• D. Magnetic force

Correct answer: B

Rationale: The correct answer is B: Frictional force. Frictional force opposes the relative motion between surfaces in contact. When two surfaces are in contact and one tries to slide over the other, the frictional force resists this motion, making it harder for the surfaces to move relative to each other. Choice A, tension force, is incorrect because tension force is a force transmitted through a string, rope, cable, or wire when it is pulled tight by forces acting from opposite ends. Choice C, gravitational force, is incorrect as it is the force of attraction between two masses. Choice D, magnetic force, is incorrect as it is the force exerted between magnetic objects.

4. What is the functional group present in amines?

• A. Hydroxyl
• B. Carbonyl
• C. Amine
• D. Nitro

Correct answer: C

Rationale: The functional group present in amines is the amine group, represented as -NH2. Amines are organic compounds characterized by the presence of a nitrogen atom bonded to hydrogen atoms. The amine group distinguishes amines from other types of organic compounds, such as alcohols with the hydroxyl group, ketones with the carbonyl group, and nitro compounds with the nitro group. Therefore, the correct answer is 'C: Amine.'

5. Which molecules are soluble in nonpolar solvents but are hydrophobic?

• A. Carbohydrates
• B. Lipids
• C. Proteins
• D. Nucleic acids

Correct answer: B

Rationale: Lipids are hydrophobic molecules that are soluble in nonpolar solvents like oils but insoluble in water. They consist of fats, oils, waxes, and steroids and play essential roles in energy storage, insulation, and cell membrane structure. Carbohydrates, proteins, and nucleic acids are not typically soluble in nonpolar solvents and do not exhibit the same hydrophobic characteristics as lipids. Carbohydrates are usually hydrophilic and soluble in water, proteins have both hydrophilic and hydrophobic regions but are not generally soluble in nonpolar solvents, and nucleic acids are polar molecules that are not known for their solubility in nonpolar solvents.

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