Nursing Elites

1. Which term refers to a molecule of DNA and structural protein?

• A. Lysosome
• B. Centrosome
• C. Chromosome
• D. Genome

Correct answer: C

Rationale: The correct answer is C: Chromosome. A chromosome is a structure composed of DNA and proteins that carries genetic information. It is the condensed form of DNA associated with structural proteins, not just a molecule of DNA or protein. Lysosomes are membrane-bound organelles containing digestive enzymes, not DNA and protein. Centrosomes are involved in cell division, not related to DNA and protein together. A genome refers to an organism's complete set of DNA, not specifically a molecule containing both DNA and structural protein.

2. Which concentration unit depends on pressure?

• A. ppm
• B. ppb
• C. molarity
• D. molarity, ppb, and ppm

Correct answer: C

Rationale: The correct answer is 'C: molarity.' Molarity is the concentration unit that depends on pressure. In molarity, the concentration of a solution is expressed as the number of moles of solute per liter of solution. This means that changes in pressure can affect the volume of the solution and consequently the concentration. Choices A and B, ppm (parts per million) and ppb (parts per billion), respectively, are independent of pressure variations as they are based on mass ratios. Therefore, molarity is the only concentration unit listed that is directly influenced by changes in pressure.

3. What is the common name for the organic compound CH₃OH?

• A. Methane
• B. Ethanol
• C. Methanol
• D. Butanol

Correct answer: C

Rationale: The common name for the organic compound CH₃OH is methanol. Methane (A) has the chemical formula CH₄. Ethanol (B) corresponds to the formula C₂H₅OH. Butanol (D) is a compound with the formula C₄H₉OH. The correct answer is C - Methanol, which is the common name for CH₃OH, while the other options correspond to different organic compounds with distinct formulas. Therefore, methanol is the correct choice when identifying the common name for the compound CH₃OH.

4. What hormone signals the release of digestive enzymes from the pancreas?

• A. Gastrin
• B. Insulin
• C. Glucagon
• D. Secretin

Correct answer: D

Rationale: A) Gastrin is a hormone that stimulates the release of gastric acid in the stomach, not digestive enzymes from the pancreas. B) Insulin is a hormone produced by the pancreas that regulates blood sugar levels by facilitating the uptake of glucose into cells, but it does not directly signal the release of digestive enzymes from the pancreas. C) Glucagon is another hormone produced by the pancreas that works opposite to insulin by increasing blood sugar levels, but it is not involved in signaling the release of digestive enzymes from the pancreas. D) Secretin is a hormone released by the small intestine in response to the presence of acidic chyme. It stimulates the pancreas to release bicarbonate to neutralize the acidity of the chyme and also triggers the release of digestive enzymes from the pancreas to aid in digestion. Therefore, secretin is the hormone that signals the release of digestive enzymes from the pancreas.

5. The innate immune system provides a non-specific first line of defense. What are some physical barriers that contribute to the innate immune system?

• A. Antibodies
• B. Phagocytes
• C. Skin and mucous membranes
• D. Memory B cells

Correct answer: C

Rationale: Physical barriers such as the skin and mucous membranes are crucial components of the innate immune system's first line of defense. These barriers act as physical obstacles that prevent pathogens from entering the body. Antibodies (option A) are produced by the adaptive immune system in response to specific pathogens and do not serve as physical barriers. Phagocytes (option B) are cells that engulf and digest pathogens, playing a role in the innate immune response but not as physical barriers. Memory B cells (option D) are part of the adaptive immune system and aid in mounting a faster and more effective immune response upon subsequent exposure to a specific pathogen, but they are not physical barriers against initial pathogen entry.

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