Nursing Elites

1. Which property of matter remains constant regardless of changes in its state?

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

Correct answer: A

Rationale: The correct answer is 'Mass.' Mass is a measure of the amount of matter in an object and remains constant regardless of changes in its state. When matter changes its state (solid, liquid, gas), its mass remains the same. On the other hand, volume can change with the shape the matter takes, density changes as the mass is distributed differently, and weight can vary with the gravitational pull. Therefore, mass is the property that remains constant irrespective of the state of matter, making it the correct choice in this scenario.

2. What unit is used for measuring luminous flux, which indicates the perceived brightness of a light source by the human eye?

• A. Candela
• B. Lumen
• C. Lux
• D. Hertz

Correct answer: B

Rationale: Lumen is the correct unit for measuring luminous flux, which quantifies the total visible light emitted by a source per unit of time. Candela measures luminous intensity, lux measures illuminance, and Hertz measures frequency. Therefore, in the context of measuring the perceived brightness of a light source by the human eye, luminous flux is quantified in lumens.

3. Which of the following best describes the relationship among density, volume, and mass?

• A. As volume increases, density decreases.
• B. As volume decreases, density increases.
• C. An object's mass does not affect its density.
• D. As volume decreases, mass increases.

Correct answer: B

Rationale: The correct answer is B: 'As volume decreases, density increases.' This is because density is defined as mass divided by volume. When volume decreases and mass remains constant, the ratio of mass to volume increases, leading to higher density. Choice A is incorrect because as volume increases, density typically remains constant or increases due to the mass also increasing. Choice C is incorrect because an object's density is directly influenced by its mass. Choice D is incorrect as decreasing volume does not lead to an increase in mass.

4. 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).

5. What is the term for a genetic disorder caused by a mutation in a mitochondrial gene?

• A. Autosomal dominant disorder
• B. Autosomal recessive disorder
• C. Sex-linked disorder
• D. Mitochondrial disorder

Correct answer: D

Rationale: A) Autosomal dominant disorder: This type of genetic disorder is caused by a mutation in one copy of an autosomal gene. It is not related to mitochondrial gene mutations. B) Autosomal recessive disorder: This type of genetic disorder is caused by mutations in both copies of an autosomal gene. It is not related to mitochondrial gene mutations. C) Sex-linked disorder: This type of genetic disorder is caused by mutations in genes located on the sex chromosomes (X or Y). It is not related to mitochondrial gene mutations. D) Mitochondrial disorder: Mitochondrial disorders are genetic disorders caused by mutations in genes located in the mitochondria, the energy-producing structures within cells. These disorders are inherited maternally and can affect various organs and systems in the body due to the role of mitochondria in energy production.

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