Nursing Elites

1. What property of a wave determines its pitch in sound waves?

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

Correct answer: B

Rationale: The pitch of a sound wave is determined by its frequency. Frequency is the number of cycles of a wave that occur in a given time period. Higher frequencies correspond to higher pitches, while lower frequencies correspond to lower pitches. Amplitude refers to the intensity or loudness of a sound wave, wavelength is the distance between two consecutive points in a wave, and speed is the rate at which a wave travels through a medium. Therefore, in sound waves, it is the frequency that primarily determines the pitch, making option B the correct answer.

2. What is the scientific unit used to measure the radioactivity of a substance?

• A. Becquerel (Bq)
• B. Joule (J)
• C. Newton (N)
• D. Kelvin (K)

Correct answer: A

Rationale: The correct answer is A: Becquerel (Bq). The Becquerel (Bq) is the scientific unit used to measure the radioactivity of a substance. It is named after Henri Becquerel, who discovered radioactivity. The Joule (J) is the unit of energy, Newton (N) is the unit of force, and Kelvin (K) is the unit of temperature. When measuring radioactivity, the Becquerel is used to quantify the rate of radioactive decay in a substance. Choices B, C, and D are incorrect as they represent units for energy, force, and temperature, respectively, not radioactivity.

3. How can a single gene mutation lead to multiple phenotypes depending on the organism?

• A. Pleiotropy describes the effect of one gene influencing multiple seemingly unrelated traits.
• B. Epigenetics involves environmental factors modifying gene expression without altering the DNA sequence.
• C. Genetic drift refers to random changes in allele frequencies within a population.
• D. Gene regulation controls the timing and level of gene expression within an organism.

Correct answer: A

Rationale: A single gene mutation can lead to multiple phenotypes through pleiotropy, where one gene influences diverse traits or functions in an organism. This phenomenon occurs when the mutated gene affects different biochemical pathways, developmental processes, or cellular functions, resulting in a cascade of downstream effects that manifest as a variety of phenotypic outcomes. Choice B, epigenetics, involves modifications in gene expression influenced by environmental factors without altering the DNA sequence, which is not directly related to the question about single gene mutations causing multiple phenotypes. Choice C, genetic drift, refers to random changes in allele frequencies within a population, which is unrelated to the impact of a single gene mutation on multiple phenotypes. Choice D, gene regulation, focuses on controlling the timing and level of gene expression within an organism, which is not directly addressing how a single gene mutation can lead to diverse phenotypes.

4. From which type of tissue is the myelin sheath derived, a fatty substance that insulates nerve fibers?

• A. Epithelial tissue
• B. Muscle tissue
• C. Nervous tissue (glial cells)
• D. Connective tissue

Correct answer: C

Rationale: The myelin sheath, a fatty substance that insulates nerve fibers, is derived from nervous tissue, specifically glial cells. Glial cells, including oligodendrocytes in the central nervous system and Schwann cells in the peripheral nervous system, are responsible for producing the myelin sheath that surrounds and insulates nerve fibers, aiding in the conduction of nerve impulses. Epithelial tissue (Choice A), Muscle tissue (Choice B), and Connective tissue (Choice D) are not responsible for producing the myelin sheath; instead, nervous tissue (glial cells) plays this crucial role.

5. Which of the following is an effect of high blood pressure?

• A. Smoking
• B. Excessive dietary salt
• C. Renal vessel damage
• D. Older age

Correct answer: C

Rationale: The correct answer is C: Renal vessel damage. High blood pressure can lead to damage in blood vessels throughout the body, including the kidneys. When blood vessels in the kidneys are affected, it can impair kidney function and potentially lead to kidney disease. Smoking (Choice A) and excessive dietary salt (Choice B) can contribute to high blood pressure but are not direct effects of high blood pressure itself. Older age (Choice D) is a risk factor for developing high blood pressure but is not a direct effect of high blood pressure.

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