Nursing Elites

1. What describes the change in direction of light when it passes through different mediums, such as air and water?

• A. Diffraction
• B. Reflection
• C. Refraction
• D. Dispersion

Correct answer: C

Rationale: Refraction is the change in direction of light as it moves from one medium to another, such as air to water or glass. This change occurs due to variations in the speed of light in each medium, causing the light rays to bend. When light passes through different mediums, it changes its path, a phenomenon known as refraction. Choice A, Diffraction, refers to the bending of waves around obstacles and the spreading of waves when passing through small openings, not the change in direction of light when moving between mediums. Choice B, Reflection, is the bouncing back of light rays from a surface into the same medium, not the change in direction when transitioning between different mediums. Choice D, Dispersion, involves the separation of light into its constituent colors based on their different wavelengths, not the change in direction of light when passing through different mediums.

2. What is the largest lymphatic vessel in the body?

• A. Jugular vein
• B. Thoracic duct
• C. Subclavian vein
• D. Aorta

Correct answer: B

Rationale: The thoracic duct is the largest lymphatic vessel in the body, responsible for draining lymph from most parts of the body except for the right upper quadrant. The jugular vein, subclavian vein, and aorta are not part of the lymphatic system; they are blood vessels and do not serve as lymphatic vessels. Therefore, choices A, C, and D are incorrect as they are not associated with the lymphatic system's transport of lymph.

3. What is the relationship between the frequency and period of a wave?

• A. They are unrelated
• B. Frequency = Period
• C. Frequency = 1/Period
• D. Period = 1/Frequency

Correct answer: D

Rationale: The correct relationship between frequency and period of a wave is that Period = 1/Frequency. This relationship indicates that the period of a wave is the reciprocal of its frequency. Frequency refers to the number of complete cycles of a wave occurring in a unit of time, while the period is the time taken for one complete cycle of the wave to occur. As frequency and period are inversely related, the correct formula to express this relationship is Period = 1/Frequency. Choice A is incorrect as frequency and period are related. Choice B is incorrect as frequency and period are not equal. Choice C is incorrect as it suggests that frequency is directly proportional to period, which is not the case.

4. During a healthy heartbeat, the P wave on an ECG represents

• A. The repolarization of the ventricles.
• B. The electrical conduction through the AV node.
• C. The contraction phase of the ventricles (systole).
• D. The depolarization of the atria.

Correct answer: D

Rationale: The P wave on an ECG represents the depolarization of the atria. This electrical activity initiates the contraction of the atria, allowing blood to be pumped into the ventricles. The P wave is the first positive deflection seen on the ECG and signifies the beginning of atrial depolarization, which is a critical step in the cardiac cycle. Choices A, B, and C are incorrect. Option A (The repolarization of the ventricles) is represented by the T wave on the ECG. Option B (The electrical conduction through the AV node) is not represented by the P wave but rather by the PR interval on the ECG. Option C (The contraction phase of the ventricles (systole)) is more related to the QRS complex on the ECG, which represents ventricular depolarization and contraction.

5. What is the process of copying DNA called?

• A. Transcription
• B. Translation
• C. Replication
• D. Mutation

Correct answer: C

Rationale: The correct answer is C, Replication. Replication is the process of making an identical copy of DNA. During replication, the DNA double helix unwinds, and each strand serves as a template for the synthesis of a new complementary strand, resulting in two identical DNA molecules. Transcription (choice A) involves the synthesis of mRNA from a DNA template, not the direct copying of DNA. Translation (choice B) is the process of converting mRNA into a sequence of amino acids to form a protein, not copying DNA. Mutation (choice D) refers to changes in the DNA sequence, which can occur during replication but is not the process of copying DNA itself.

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