Nursing Elites

1. What is the pH of a solution with a hydrogen ion concentration of (1x10^{-9}) M?

• A. 5
• B. 7
• C. 9
• D. 11

Correct answer: C

Rationale: The pH of a solution can be calculated using the formula: pH = -log[H+]. Given that the hydrogen ion concentration is \(1 \times 10^{-9}\) M, the pH can be calculated as pH = -log(1 x 10^-9) = 9. Therefore, the correct answer is C) 9.

2. What is an isotope? For any given element, it is an atom with which of the following?

• A. a different atomic number
• B. a different number of protons
• C. a different number of electrons
• D. a different mass number

Correct answer: D

Rationale: An isotope of an element is an atom with a different number of neutrons, resulting in a different mass number. Isotopes of the same element have the same number of protons (which determines the element's identity) but differ in the number of neutrons, leading to variations in mass numbers. Choice A is incorrect because isotopes of the same element have the same atomic number. Choice B is incorrect because isotopes of the same element have the same number of protons. Choice C is incorrect because isotopes of the same element have the same number of electrons.

3. What is a gene, and what is the relationship between genes, genotype, and phenotype?

• A. A gene is a sequence of amino acids; genes make up proteins; genotype determines phenotype
• B. A gene is a portion of DNA; genes determine traits; genotype is the genetic makeup; phenotype is the physical manifestation
• C. A gene is a protein; proteins determine traits; genotype is the set of all genes
• D. A gene is a lipid; lipids determine traits; phenotype is the physical manifestation

Correct answer: B

Rationale: A gene is a portion of DNA that contains the instructions for a specific trait. Genotype refers to the genetic makeup of an organism, encompassing all its genes. Phenotype, on the other hand, is the observable physical manifestation resulting from the interaction between an organism's genotype and environmental factors. Choice A is incorrect because genes do not consist of amino acids directly; they are sequences of nucleotides. Choice C is incorrect as genes do not determine traits directly but provide the instructions for proteins that may influence traits. Choice D is incorrect as genes are not lipids, and lipids do not determine traits; they are a type of biomolecule with different functions.

4. The small intestine is where most of the chemical digestion and nutrient absorption occur. What is the finger-like projection in the small intestine that increases its surface area for absorption?

• A. Rugae
• B. Villi
• C. Microvilli
• D. All of the above

Correct answer: C

Rationale: Microvilli are the finger-like projections in the small intestine that increase its surface area for absorption. Villi are also present in the small intestine and help increase the surface area for absorption. However, microvilli are smaller structures found on the surface of villi, further increasing the surface area available for nutrient absorption. Rugae are folds in the stomach that allow for expansion when food is consumed and are not found in the small intestine. Therefore, the correct answer is C) Microvilli. Villi and microvilli are specific to the small intestine, playing vital roles in nutrient absorption, while rugae are specific to the stomach's structure and function, serving a different purpose than increasing surface area for absorption.

5. What happens to the kinetic energy of an object when its velocity is doubled?

• A. Kinetic energy remains the same
• B. Kinetic energy is halved
• C. Kinetic energy doubles
• D. Kinetic energy quadruples

Correct answer: C

Rationale: Kinetic energy is directly proportional to the square of the velocity of an object according to the kinetic energy formula (KE = 0.5 * m * v^2). When the velocity is doubled, the kinetic energy increases by a factor of four (2^2), which means it doubles. Therefore, when the velocity of an object is doubled, its kinetic energy also doubles. Choice A is incorrect because kinetic energy is not constant but dependent on velocity. Choice B is incorrect because halving the velocity would result in 1/4 of the original kinetic energy. Choice D is incorrect as quadrupling the kinetic energy would occur if the velocity is squared, not the kinetic energy.

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