Nursing Elites

1. Which property of a substance measures the amount of matter per unit volume?

• A. Density
• B. Mass
• C. Weight
• D. Volume

Correct answer: A

Rationale: Density is the property of a substance that measures the amount of matter per unit volume. It is calculated by dividing the mass of the substance by its volume. Mass refers to the amount of matter in an object, weight is the force of gravity acting on an object, and volume is the amount of space an object occupies. Density specifically quantifies how tightly packed the matter in a substance is, providing a measure of compactness or concentration of matter. Therefore, the correct answer is A, Density.

2. Which of the following is an example of an aromatic compound?

• A. Ethanol
• B. Toluene
• C. Acetone
• D. Butanal

Correct answer: B

Rationale: Toluene is an aromatic compound due to its benzene ring structure, which satisfies the criteria of aromaticity. Aromatic compounds contain conjugated pi electrons in a ring structure, providing extra stability. Ethanol, acetone, and butanal are not aromatic compounds as they do not possess a benzene ring or meet the aromaticity criteria. Ethanol is an alcohol, acetone is a ketone, and butanal is an aldehyde, none of which have the characteristic benzene ring structure of aromatic compounds.

3. What is the difference between active and passive immunity?

• A. Active immunity is short-lived, while passive immunity is long-lasting.
• B. Active immunity involves the body's own immune response, while passive immunity provides immediate protection through antibodies from another source.
• C. Active immunity only protects against bacterial infections, while passive immunity works against both bacteria and viruses.
• D. Passive immunity requires repeated vaccinations, while active immunity is a one-time process.

Correct answer: B

Rationale: Active immunity involves the body's own immune response, where the individual's immune system produces antibodies in response to exposure to a pathogen or vaccine. This type of immunity is long-lasting because the immune system 'remembers' the pathogen and can mount a rapid response upon re-exposure. In contrast, passive immunity provides immediate protection through the transfer of pre-formed antibodies from another source, such as through maternal antibodies crossing the placenta or receiving antibodies through an injection. Passive immunity is short-lived because the transferred antibodies eventually degrade and are not produced by the recipient's immune system. Choice A is incorrect because active immunity is generally long-lasting, as it involves the production of antibodies by the individual's immune system. Choice C is incorrect as both active and passive immunity can work against various pathogens, not limited to bacteria or viruses. Choice D is incorrect as passive immunity does not require repeated vaccinations but provides temporary protection through the transfer of antibodies from an external source.

4. Which organ in the human body is responsible for filtering blood and producing urine?

• A. Liver
• B. Kidneys
• C. Pancreas
• D. Heart

Correct answer: B

Rationale: The correct answer is B: Kidneys. The kidneys are vital organs in the human body responsible for filtering blood to remove waste products and excess substances, producing urine as a result. The liver plays a role in detoxification and metabolism. The pancreas is involved in digestion and blood sugar regulation. The heart pumps blood throughout the body but does not filter blood or produce urine.

5. Which type of cells make up the myelin sheaths?

• A. Glial cells.
• B. Dendrites.
• C. Melanocytes.
• D. Squamous cells.

Correct answer: A

Rationale: The correct answer is A: Glial cells. Glial cells are responsible for producing the myelin sheaths that surround and insulate nerve cells in the central and peripheral nervous systems. Schwann cells in the peripheral nervous system and oligodendrocytes in the central nervous system are types of glial cells that form the myelin sheaths. Choice B, dendrites, are not involved in forming myelin sheaths; they are extensions of neurons that receive signals. Choice C, melanocytes, are cells responsible for producing melanin, not myelin. Choice D, squamous cells, are flat epithelial cells found in various tissues but are not involved in myelin sheath formation.

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