Nursing Elites

1. What is the function of the pericardium, the sac surrounding the heart?

• A. To generate electrical impulses for heart contraction
• B. To transport blood throughout the body
• C. To provide lubrication for heart movement
• D. To protect the heart and anchor it in place

Correct answer: C

Rationale: The pericardium is a double-walled sac that surrounds the heart and contains a small amount of fluid to provide lubrication for the movement of the heart within the chest cavity. It helps reduce friction as the heart beats and moves. Choice A is incorrect because the generation of electrical impulses for heart contraction is primarily the function of the heart's specialized conduction system. Choice B is incorrect as the pericardium is not involved in the transportation of blood throughout the body. Choice D is also incorrect as while the pericardium does protect the heart, its primary function is to provide lubrication and reduce friction.

2. Which of the following is an example of a polymer?

• A. Methane
• B. Ethanol
• C. Polyethylene
• D. Acetic acid

Correct answer: C

Rationale: The correct answer is C, Polyethylene. Polyethylene is a polymer composed of a large number of repeating ethylene units linked together, forming a long-chain molecule, characteristic of polymers. Methane, ethanol, and acetic acid are small organic molecules that do not demonstrate the repeating unit structure typical of polymers. Therefore, they are not examples of polymers.

3. Which property of a substance refers to its ability to be hammered or pressed into thin sheets without breaking?

• A. Malleability
• B. Ductility
• C. Viscosity
• D. Conductivity

Correct answer: A

Rationale: Malleability is the correct answer as it is the property of a substance that allows it to be hammered or pressed into thin sheets without breaking. This property is crucial for materials like metals that need to be shaped without breaking. Ductility, on the other hand, refers to the ability of a substance to be drawn into thin wires, not hammered into sheets. Viscosity is a measure of a fluid's resistance to flow, indicating its thickness or thinness, and is unrelated to the ability to be hammered. Conductivity, on the other hand, refers to a substance's ability to conduct electricity or heat, which is not related to its ability to be hammered or pressed into thin sheets.

4. What type of bond links amino acids together to form proteins?

• A. Hydrogen bond
• B. Ionic bond
• C. Disulfide bond
• D. Covalent bond

Correct answer: D

Rationale: Amino acids are linked together by covalent bonds to form proteins. Specifically, the bond that links amino acids together is called a peptide bond, which is a type of covalent bond. The peptide bond forms between the amino group of one amino acid and the carboxyl group of another amino acid, resulting in the formation of a peptide chain. While hydrogen bonds, ionic bonds, and disulfide bonds are important for protein structure and stability, the primary bond responsible for linking amino acids in a protein chain is the covalent peptide bond. Hydrogen bonds are involved in maintaining the secondary structure of proteins, such as alpha helices and beta sheets. Ionic bonds and disulfide bonds contribute to tertiary and quaternary structures of proteins by stabilizing interactions between different parts of the protein or between different protein subunits, respectively.

5. Which type of wave does not require a medium for propagation?

• A. Transverse wave
• B. Longitudinal wave
• C. Mechanical wave
• D. Electromagnetic wave

Correct answer: D

Rationale: The correct answer is D, Electromagnetic wave. Electromagnetic waves do not require a medium for propagation because they consist of oscillating electric and magnetic fields that can travel through a vacuum. In contrast, transverse and longitudinal waves are mechanical waves that require a medium (solid, liquid, or gas) for propagation. Therefore, options A, B, and C are incorrect as they are all types of mechanical waves that necessitate a medium for transmission.

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