Nursing Elites

1. Alpha waves, characteristic of quiet wakefulness and relaxation, have a frequency range of:

• A. 0.5-4 Hz
• B. 4-8 Hz
• C. 8-13 Hz
• D. 13-30 Hz

Correct answer: C

Rationale: Alpha waves are neural oscillations in the frequency range of 8-13 Hz, which are typically associated with a state of quiet wakefulness and relaxation. Option C, 8-13 Hz, is the correct frequency range for alpha waves. Choices A, B, and D are incorrect as they do not fall within the specific frequency range characteristic of alpha waves.

2. The critical angle is defined as the minimum angle of incidence in a denser medium for which light undergoes:

• A. Total internal reflection
• B. Continued refraction
• C. Specular reflection
• D. Increased dispersion

Correct answer: A

Rationale: The critical angle is the minimum angle of incidence in a denser medium at which light undergoes total internal reflection instead of refraction. This phenomenon occurs when light travels from a denser medium to a less dense medium, and the angle of incidence is greater than the critical angle. Total internal reflection is a crucial concept in optics and is utilized in various applications such as fiber optics and prisms. Choice B, 'Continued refraction,' is incorrect as the critical angle specifically marks the point at which total internal reflection occurs, not continued refraction. Choice C, 'Specular reflection,' does not accurately describe the phenomenon associated with the critical angle. Choice D, 'Increased dispersion,' is unrelated to the concept of the critical angle and does not describe the behavior of light at this specific point.

3. What does potency refer to in regards to cells?

• A. The cell's ability to survive
• B. The cell's ability to move
• C. The cell's ability to divide rapidly
• D. The cell's ability to differentiate

Correct answer: D

Rationale: Potency refers to a cell's potential to differentiate into different cell types. It is not related to the cell's ability to survive (Choice A), move (Choice B), or divide rapidly (Choice C). Stem cells, for example, exhibit varying degrees of potency based on their capacity to give rise to various cell types. Therefore, the correct answer is D as it accurately defines the concept of potency in cells.

4. Myelin sheath is a fatty substance that insulates and protects the long extensions of some nerve cells. It is produced by:

• A. Schwann cells
• B. Astrocytes
• C. Neurons
• D. Oligodendrocytes

Correct answer: A

Rationale: Schwann cells are indeed responsible for producing the myelin sheath in the peripheral nervous system. These cells wrap around axons to form the myelin sheath, which enhances the speed of nerve impulse conduction. In the central nervous system, oligodendrocytes are responsible for producing the myelin sheath. Astrocytes provide support and maintenance functions for neurons, while neurons are the nerve cells themselves and do not produce myelin. Therefore, the correct answer is Schwann cells as they are specifically involved in myelin production in the peripheral nervous system.

5. Which enzyme plays a crucial role in DNA replication during the S phase of interphase?

• A. Helicase
• B. DNA polymerase
• C. Ligase
• D. Topoisomerase

Correct answer: B

Rationale: During the S phase of interphase, DNA replication takes place. DNA polymerase is the enzyme responsible for synthesizing new DNA strands by adding nucleotides in a complementary manner to the template strand. It plays a pivotal role in accurately replicating the entire genome. While helicase unwinds the double-stranded DNA for replication, topoisomerase relieves the tension in the DNA strands, and ligase joins the Okazaki fragments on the lagging strand. However, DNA polymerase directly participates in the synthesis of new DNA strands during replication, making it the correct answer.

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