Nursing Elites

1. During normal breathing, which muscle is the primary driver of inhalation by contracting and flattening to increase the volume of the thoracic cavity?

• A. Diaphragm
• B. Intercostal muscles
• C. Abdominal muscles
• D. Pectoral muscles

Correct answer: A

Rationale: The diaphragm is the primary muscle responsible for inhalation during normal breathing. When it contracts, it flattens, increasing the volume of the thoracic cavity and creating a negative pressure that allows air to flow into the lungs. Intercostal muscles also play a role in expanding the chest cavity during inhalation, but the diaphragm is the main driver of the process. Abdominal muscles are primarily involved in exhalation by pushing the diaphragm upward to expel air from the lungs. Pectoral muscles are involved in movements of the arms and shoulders, not in breathing, making them incorrect choices for this question.

2. Which macromolecule serves as the repository of genetic information in all living organisms?

• A. Ribonucleic acid (RNA)
• B. Deoxyribonucleic acid (DNA)
• C. Protein
• D. Carbohydrate

Correct answer: B

Rationale: - DNA is the macromolecule that serves as the repository of genetic information in all living organisms. It carries the genetic instructions necessary for the growth, development, functioning, and reproduction of organisms. - RNA (option A) is involved in various cellular processes, including protein synthesis, but DNA is the primary molecule responsible for storing genetic information. - Proteins (option C) are essential for various cellular functions but do not serve as the primary repository of genetic information. - Carbohydrates (option D) are important for energy storage and structural support but do not store genetic information.

3. Which of the following are the blood vessels that transport blood away from the heart?

• A. arteries
• B. capillaries
• C. venules
• D. veins

Correct answer: A

Rationale: Arteries are blood vessels that carry oxygen-rich blood away from the heart to various parts of the body. Therefore, they are the vessels that transport blood away from the heart. Veins, on the other hand, transport blood back to the heart. Capillaries are tiny blood vessels where the exchange of nutrients and waste products occurs between blood and tissues, not vessels that transport blood to the heart. Venules are small veins that collect blood from capillaries and connect them to larger veins, rather than transport blood to the heart.

4. What is the electrical charge of the nucleus?

• A. A nucleus always has a positive charge.
• B. A stable nucleus has a positive charge, but a radioactive nucleus may have no charge and instead be neutral.
• C. A nucleus always has no charge and is instead neutral.
• D. A stable nucleus has no charge and is instead neutral, but a radioactive nucleus may have a charge.

Correct answer: A

Rationale: A nucleus always has a positive charge. This is because the nucleus is composed of positively charged protons, along with neutral neutrons. The positive charge of the protons is balanced by the negative charge of the surrounding electrons in an atom, resulting in an overall neutral charge for the atom as a whole. Therefore, choice A is correct as it accurately reflects the positive charge of the nucleus due to the presence of protons. Choices B, C, and D are incorrect because they do not accurately represent the fundamental composition and charge distribution within an atom's nucleus. A stable nucleus consists of positively charged protons and neutral neutrons, leading to an overall positive charge, and not a neutral charge as suggested in the incorrect choices.

5. Which level of protein structure is defined by the folds and coils of the protein's polypeptide backbone?

• A. Primary
• B. Secondary
• C. Tertiary
• D. Quaternary

Correct answer: B

Rationale: The correct answer is B: Secondary. The secondary structure of a protein is defined by the folds and coils of the protein's polypeptide backbone. This level of structure is characterized by the formation of alpha helices and beta sheets, which are stabilized by hydrogen bonds between amino acids along the polypeptide chain. Choice A, Primary, refers to the linear sequence of amino acids in the protein. Choice C, Tertiary, involves the 3D folding of the entire polypeptide chain. Choice D, Quaternary, pertains to the arrangement of multiple polypeptide subunits in a protein complex.

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