Nursing Elites

1. Which of the following is directly transcribed from DNA and represents the first step in protein synthesis?

• A. siRNA
• B. rRNA
• C. mRNA
• D. tRNA

Correct answer: C

Rationale: mRNA (messenger RNA) is directly transcribed from DNA in the nucleus during the process of transcription. It serves as a template for protein synthesis during translation in the cytoplasm. mRNA carries genetic information from the DNA to the ribosomes, where it determines the sequence of amino acids in a protein. Thus, mRNA represents the first step in protein synthesis as it carries the code from the DNA to be translated into a protein. Choice A, siRNA (small interfering RNA), is involved in post-transcriptional gene silencing and does not play a role in protein synthesis. Choice B, rRNA (ribosomal RNA), is a component of the ribosome and plays a structural and functional role in protein synthesis but is not directly transcribed from DNA. Choice D, tRNA (transfer RNA), is responsible for bringing amino acids to the ribosome during protein synthesis but is not directly transcribed from DNA.

2. What is the process by which simple cells become highly specialized cells?

• A. Cellular complication
• B. Cellular specialization
• C. Cellular differentiation
• D. Cellular modification

Correct answer: C

Rationale: The correct answer is 'Cellular differentiation'. Cellular differentiation is the process by which simple cells become highly specialized cells. During cellular differentiation, cells acquire specific structures and functions that allow them to perform particular roles within an organism. This process involves the activation and silencing of specific genes, leading to the development of various cell types with distinct characteristics and functions. 'Cellular complication' (Choice A) is incorrect as it does not describe the specific process of cells becoming specialized. 'Cellular specialization' (Choice B) is not the most precise term for the process, as it does not capture the transformation from simple cells to specialized cells. 'Cellular modification' (Choice D) is incorrect as it is a vague term that does not specifically refer to the process of cellular specialization.

3. Which mineral is essential for muscle function and nerve transmission?

• A. Calcium
• B. Iron
• C. Sodium
• D. Potassium

Correct answer: D

Rationale: Potassium is the correct answer as it is essential for muscle function and nerve transmission. Potassium plays a crucial role in regulating muscle contractions, including the heart's beating, and is vital for transmitting electrical signals within the nervous system. Calcium (Choice A) is important for muscle contraction but is not the primary mineral for nerve transmission. Iron (Choice B) is important for oxygen transport in the blood. Sodium (Choice C) is important for fluid balance but is not primarily responsible for muscle function and nerve transmission.

4. In the 18th century, women were more likely to die in childbirth compared to the 21st century. What is a possible explanation for why women are less likely to die in childbirth in the present age?

• A. Doctors are better equipped to perform cesarean sections.
• B. Doctors have more tools to monitor mothers during childbirth, enabling earlier detection of complications.
• C. Doctors practice good hand hygiene to prevent the transfer of germs and infections.
• D. All of the statements above provide reasonable explanations for the decrease in mortality during childbirth.

Correct answer: D

Rationale: All options are valid explanations for the decrease in maternal mortality during childbirth in modern times. Improved medical knowledge and technology have enabled doctors to perform cesarean sections more effectively, monitor mothers more closely for early detection of complications, and maintain better hygiene practices to reduce the risk of infections. Therefore, all the given statements collectively contribute to the reduction in maternal mortality rates in the 21st century.

5. What property of matter explains why ice floats on water?

• A. Viscosity
• B. Density
• C. Buoyancy
• D. Surface tension

Correct answer: C

Rationale: The correct answer is C, buoyancy. Ice floats on water due to buoyancy, a property of matter. When water freezes into ice, it becomes less dense than liquid water, causing it to float. This phenomenon occurs because the molecules in ice are more spread out compared to liquid water, resulting in ice being less dense and able to float on the surface. Choice A, viscosity, is incorrect because viscosity refers to a fluid's resistance to flow, not its ability to float. Choice B, density, is incorrect because while ice being less dense than water is the reason it floats, this choice does not explain the specific property that causes this phenomenon. Choice D, surface tension, is incorrect as it pertains to the cohesive forces between molecules at the surface of a liquid, not the reason why ice floats on water.

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