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 of the following cations is found at the center of a heme?

• A. Cr (III)
• B. Cu (II)
• C. Iron (II)
• D. Iron (III)

Correct answer: C

Rationale: The correct answer is Iron (II) (Fe2+), which is the cation found at the center of a heme group. Heme contains an iron (II) ion that is coordinated within the porphyrin ring structure. This iron ion is crucial for the function of heme in binding and transporting oxygen in hemoglobin and myoglobin. Choice A (Cr (III)) is incorrect as chromium is not typically found at the center of a heme group. Choice B (Cu (II)) is incorrect as copper is not the cation typically present in heme. Choice D (Iron (III)) is also incorrect as heme predominantly contains iron (II) at its center, not iron (III).

3. Approximately how many muscles are in the human body?

• A. 100
• B. 200
• C. 600
• D. Over 600

Correct answer: D

Rationale: The human body has over 600 muscles responsible for various functions like movement, stability, and posture. These muscles work together enabling us to perform daily activities and are crucial for our overall health and well-being. Choices A, B, and C are incorrect because the human body has far more than 100, 200, or 600 muscles. Option D, 'Over 600,' is the correct answer as it accurately reflects the approximate number of muscles in the human body.

4. What is the process of transporting molecules across the cell membrane against a concentration gradient called?

• A. Diffusion
• B. Osmosis
• C. Active transport
• D. Facilitated diffusion

Correct answer: C

Rationale: A) Diffusion is the movement of molecules from an area of higher concentration to an area of lower concentration, which does not require energy input. B) Osmosis is the movement of water molecules across a selectively permeable membrane from an area of lower solute concentration to an area of higher solute concentration. C) Active transport is the process of transporting molecules across the cell membrane against a concentration gradient, requiring energy in the form of ATP to move substances from an area of lower concentration to an area of higher concentration. D) Facilitated diffusion is a type of passive transport that involves the use of transport proteins to move molecules across the cell membrane from an area of higher concentration to an area of lower concentration, without the need for energy input.

5. In the reaction 2H2 + O2 → 2H2O, how many moles of oxygen are required to react completely with 4 moles of hydrogen?

• A. 1
• B. 2
• C. 3
• D. 4

Correct answer: B

Rationale: The balanced chemical equation indicates that 2 moles of H2 react with 1 mole of O2 to produce 2 moles of H2O. To determine how many moles of O2 are required to react with 4 moles of H2, you can use the mole ratio from the balanced equation: 2 moles of H2 react with 1 mole of O2. Therefore, to react completely with 4 moles of H2, you would need 2 moles of O2 (4 moles H2 ÷ 2 moles H2 per 1 mole O2). Hence, 2 moles of oxygen are required to react completely with 4 moles of hydrogen. Choices A, C, and D are incorrect because they do not reflect the correct stoichiometry as defined by the balanced chemical equation.

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