Nursing Elites

1. What are the three main types of RNA?

• A. Messenger RNA (mRNA), ribosomal RNA (rRNA), and transfer RNA (tRNA)
• B. DNA, RNA, and protein
• C. Adenine, guanine, cytosine, and thymine
• D. Deoxyribose, ribose, and phosphate

Correct answer: A

Rationale: - Messenger RNA (mRNA) carries genetic information from the DNA in the nucleus to the ribosomes in the cytoplasm for protein synthesis. - Ribosomal RNA (rRNA) is a structural component of ribosomes, which are the cellular machinery responsible for protein synthesis. - Transfer RNA (tRNA) is responsible for bringing amino acids to the ribosome during protein synthesis. Options B, C, and D are incorrect: - Option B lists DNA, RNA, and protein, which are biomolecules but not the three main types of RNA. - Option C lists nitrogenous bases (adenine, guanine, cytosine, and thymine) found in DNA, not types of RNA. - Option D lists components of nucleotides (deoxyribose, ribose, and phosphate), which are building blocks of nucleic

2. Which vitamin is synthesized in the skin upon exposure to sunlight?

• A. Vitamin A
• B. Vitamin C
• C. Vitamin D
• D. Vitamin E

Correct answer: C

Rationale: Vitamin D is synthesized in the skin upon exposure to sunlight. When the skin is exposed to sunlight, a form of cholesterol in the skin is converted into vitamin D3 (cholecalciferol) through a series of chemical reactions. Vitamin D plays a crucial role in calcium absorption and bone health. Choice A, Vitamin A, is not synthesized in the skin upon exposure to sunlight; it is obtained through dietary sources. Choice B, Vitamin C, is not synthesized in the skin upon exposure to sunlight either. Vitamin C is obtained through dietary sources like fruits and vegetables. Choice D, Vitamin E, is not synthesized in the skin upon exposure to sunlight. Vitamin E is a fat-soluble vitamin that acts as an antioxidant and is obtained through dietary sources like nuts, seeds, and vegetable oils.

3. What is the process in which RNA polymerase copies DNA into RNA, with DNA unwinding and serving as a template while RNA is assembled?

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

Correct answer: B

Rationale: The correct answer is B: Transcription. Transcription is the process where RNA polymerase reads the DNA template strand and synthesizes RNA, following the base-pairing rules. During transcription, DNA unwinds and serves as a template for the assembly of complementary RNA molecules. Replication (Choice A) is the process of making an identical copy of DNA, not RNA from DNA. Translation (Choice C) is the process of synthesizing proteins from mRNA. Duplication (Choice D) is a general term and does not specifically refer to the process described in the question.

4. During vigorous exercise, why does the respiratory rate increase?

• A. Meet the increased demand for oxygen in working muscles
• B. Eliminate excess carbon dioxide more slowly
• C. Conserve energy for physical activity
• D. Decrease the amount of oxygen delivered to the body

Correct answer: A

Rationale: During vigorous exercise, the muscles require more oxygen to produce energy for physical activity. The increased respiratory rate helps to deliver more oxygen to the working muscles to meet this demand. This process is essential for sustaining physical activity and preventing fatigue. Choice A is the correct answer as it accurately describes the purpose of the increased respiratory rate during vigorous exercise. Choices B, C, and D are incorrect. Choice B, 'Eliminate excess carbon dioxide more slowly,' is inaccurate as the primary reason for the increased respiratory rate during exercise is to meet the increased demand for oxygen, not to eliminate carbon dioxide. Choice C, 'Conserve energy for physical activity,' is incorrect because increasing the respiratory rate actually expends energy to meet the oxygen demand of the working muscles. Choice D, 'Decrease the amount of oxygen delivered to the body,' is incorrect as the increased respiratory rate is specifically to deliver more oxygen to the body during exercise.

5. What happens to the speed of a sound wave when it travels from air to water?

• A. It increases because water is denser.
• B. It decreases because water is denser.
• C. It remains the same.
• D. Speed depends on the frequency, not the medium.

Correct answer: B

Rationale: When a sound wave travels from air to water, the speed of sound decreases because sound travels faster in denser mediums. Water, being denser than air, causes the speed of sound to slow down. Choice A is incorrect because sound travels faster in denser mediums, so the speed would not increase. Choice C is incorrect because the speed of sound changes when transitioning between different mediums. Choice D is incorrect because while frequency does affect sound, the medium it travels through also plays a significant role in determining the speed of sound.

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