Nursing Elites

1. Which of the following is an example of an unsaturated fatty acid?

• A. Stearic acid
• B. Palmitic acid
• C. Oleic acid
• D. Butyric acid

Correct answer: C

Rationale: Oleic acid is an example of an unsaturated fatty acid because it contains one or more double bonds in its hydrocarbon chain, leading to kinks in the chain structure. This unsaturation gives it a lower melting point compared to saturated fatty acids. Stearic acid (A), Palmitic acid (B), and Butyric acid (D) are examples of saturated fatty acids as they do not contain any double bonds in their hydrocarbon chains, leading to a straight structure and higher melting points.

2. Which blood vessels transport blood from the capillaries back to the heart?

• A. Arterioles
• B. Veins
• C. Venules
• D. Capillaries

Correct answer: B

Rationale: Veins are the correct answer as they are the blood vessels that carry blood from the capillaries back to the heart. Veins have thinner walls compared to arteries and contain valves to prevent blood from flowing backward. This transport of blood from the capillaries to the heart is essential for the circulatory system to maintain proper blood flow and oxygenation levels. Arterioles are small branches of arteries that lead to capillaries, not vessels that transport blood back to the heart. Venules are small vessels that collect blood from capillaries and lead to veins. Capillaries are the smallest blood vessels where the exchange of gases and nutrients occurs between blood and tissues, not vessels that transport blood back to the heart.

3. Molecular clocks utilize the accumulation of mutations in DNA sequences to estimate the evolutionary divergence time between species. This method relies on the assumption that:

• A. The rate of mutation is constant across all genes and all species.
• B. Species with more morphological similarities diverged more recently.
• C. Mutations are always beneficial and contribute to increased fitness.
• D. The fossil record provides the most accurate estimates of evolutionary relationships.

Correct answer: A

Rationale: A molecular clock is a method used to estimate the time of divergence between species by measuring the accumulation of mutations in DNA sequences. This method relies on the assumption that mutations occur at a relatively constant rate over time. If the rate of mutation were not constant, it would be challenging to accurately estimate the evolutionary divergence time between species. Therefore, option A is the most appropriate choice as it aligns with the fundamental principle underlying the molecular clock hypothesis. Option B is incorrect because the assumption that species with more morphological similarities diverged more recently does not directly relate to the concept of molecular clocks and the accumulation of mutations in DNA sequences. Option C is incorrect because mutations are not always beneficial and do not always contribute to increased fitness. Mutations can be neutral or deleterious as well, and their accumulation is what is used to estimate evolutionary di

4. Which property of matter remains constant regardless of changes in gravity?

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

Correct answer: A

Rationale: Mass is a measure of the amount of matter in an object and remains constant regardless of changes in gravity. Weight, on the other hand, is the force of gravity acting on an object and can vary depending on the strength of gravity. Volume is the amount of space an object occupies, and density is the mass per unit volume of a substance, both of which can change with changes in gravity. Therefore, mass is the property that remains the same regardless of variations in gravitational force. Choice B, Weight, changes with gravity as it is a force dependent on gravity. Choices C and D, Volume and Density, can be affected by changes in gravity as they are related to the space an object occupies and the mass per unit volume, respectively.

5. Which property of a wave remains constant when it crosses a boundary between two different media?

• A. Frequency
• B. Wavelength
• C. Amplitude
• D. Speed

Correct answer: D

Rationale: When a wave crosses a boundary between two different media, its speed is the property that remains constant. This is due to the principle of conservation of energy. While the frequency and wavelength of a wave may change as it moves from one medium to another, the speed of the wave remains constant. This phenomenon is a result of the wave adjusting its frequency and wavelength to maintain a consistent speed in different media. Therefore, choices A, B, and C are incorrect. Frequency and wavelength may change when a wave moves across media, and amplitude may also be affected by the medium, but the speed of the wave will remain constant.

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