Nursing Elites

1. Which of the following has a smaller genetic scale than a chromosome?

• A. Genome
• B. Gene
• C. DNA
• D. All of the above

Correct answer: B

Rationale: The correct answer is 'B: Gene.' A gene is a segment of DNA and is smaller in scale than a chromosome. Genes are the fundamental units of heredity, containing the instructions for building and maintaining an organism. While a chromosome is a larger structure that carries many genes, each gene is a specific segment of DNA responsible for encoding a particular protein or RNA molecule. Choices A, C, and D are incorrect. The 'Genome' (Choice A) refers to the complete set of an organism's genetic material, including all of its genes, while 'DNA' (Choice C) is the molecule that carries the genetic instructions. 'All of the above' (Choice D) is incorrect because not all options have a smaller genetic scale than a chromosome.

2. Which term describes the quantity of matter in an object and is measured in kilograms or grams?

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

Correct answer: B

Rationale: Mass is the quantity of matter in an object and is commonly measured in kilograms or grams. It is a fundamental property of matter and remains constant regardless of the object's location. Weight, in contrast, refers to the force of gravity acting on an object and is measured in newtons. Volume represents the amount of space an object occupies and is typically measured in cubic units like cubic meters or cubic centimeters. Density, on the other hand, is the mass of an object per unit volume, and its unit is, for example, kilograms per cubic meter. Therefore, the correct answer is 'Mass' as it specifically describes the quantity of matter in an object, regardless of the gravitational pull on it. 'Weight,' 'Volume,' and 'Density' do not directly represent the quantity of matter in an object but rather different properties related to it.

3. What are energy levels and orbitals?

• A. Energy levels are the paths that electrons travel around the nucleus of an atom, and orbitals are the regions where electrons are most likely to be found.
• B. Energy levels are the regions where electrons are most likely to be found, and orbitals are the paths that electrons travel around the nucleus of an atom.
• C. Energy levels are the same as orbitals.
• D. Energy levels and orbitals do not exist.

Correct answer: A

Rationale: Energy levels refer to the specific energies that electrons in an atom can have, while orbitals are the regions within an atom where electrons are most likely to be found. Electrons do not travel in fixed paths around the nucleus like planets around the sun, as suggested in option B. Option C is incorrect because energy levels and orbitals are distinct concepts in atomic structure. Option D is incorrect as energy levels and orbitals are fundamental concepts in understanding the behavior of electrons in atoms.

4. What is the net ionic equation for the reaction: 2HCl(aq) + Ba(OH)2(aq) → 2H2O(l) + BaCl2(aq)?

• A. 2H+(aq) + 2OH-(aq) → 2H2O(l)
• B. 2HCl(aq) + Ba(OH)2(aq) → BaCl2(aq) + 2H2O(l)
• C. 2H+(aq) + Ba2+(aq) → Ba2+(aq) + 2H+(aq)
• D. Ba(OH)2(aq) + HCl(aq) → BaCl2(aq) + 2H2O(l)

Correct answer: A

Rationale: In the given reaction, the complete ionic equation is: 2H+(aq) + 2Cl-(aq) + Ba2+(aq) + 2OH-(aq) → 2H2O(l) + Ba2+(aq) + 2Cl-(aq). Spectator ions (Ba2+ and Cl-) do not participate in the net ionic equation, which simplifies to: 2H+(aq) + 2OH-(aq) → 2H2O(l). This equation represents the significant species involved in the reaction, showcasing the formation of water from the combination of hydrogen ions and hydroxide ions, resulting in the production of water molecules.

5. Which of the following are functions of the urinary system?

• A. I, II, and III
• B. II and III
• C. II, III, and IV
• D. All of the above

Correct answer: D

Rationale: The corrected answer is D, 'All of the above.' The urinary system performs multiple essential functions to maintain the body's internal environment. Synthesizing calcitriol and secreting erythropoietin are crucial roles of the kidneys. Regulating the concentrations of sodium, potassium, chloride, calcium, and other ions helps in maintaining the electrolyte balance. Reabsorbing or secreting hydrogen ions and bicarbonate is vital for managing the body's acid-base balance. Furthermore, the urinary system is involved in detecting reductions in blood volume and pressure, aiding in the maintenance of blood pressure levels and fluid balance in the body.

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