Nursing Elites

1. Which part of the spinal cord is responsible for transmitting sensory information from the body to the brain?

• A. Dorsal root
• B. Ventral root
• C. Gray matter
• D. White matter

Correct answer: A

Rationale: The correct answer is the dorsal root. The dorsal root of the spinal cord contains sensory nerve fibers that transmit sensory information from the body to the brain. This information includes touch, pain, temperature, and proprioception. The ventral root, on the other hand, contains motor nerve fibers responsible for carrying signals from the brain to the muscles and glands, controlling movement and glandular functions. Gray matter, consisting mainly of cell bodies, is involved in processing and integrating sensory and motor information within the spinal cord. White matter is primarily composed of myelinated axons that facilitate communication between different regions of the nervous system, allowing signals to travel efficiently within the spinal cord and between the brain and other parts of the body. Therefore, the dorsal root is specifically associated with transmitting sensory information, making it the correct answer in this context.

2. 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.

3. At which step in the scientific method might a scientist create a model?

• A. Hypothesis
• B. Data analysis
• C. Experimentation
• D. Conclusion

Correct answer: A

Rationale: In the scientific method, scientists often create models during the hypothesis stage. Creating models at this stage helps visualize or simulate ideas before proceeding to experimentation and data analysis. Models are valuable tools that allow scientists to conceptualize and test their ideas before conducting experiments to gather data and draw conclusions. Therefore, the correct answer is A. Choice B, data analysis, occurs after experiments have been conducted and data has been collected, making it an incorrect choice. Choice C, experimentation, involves conducting tests and observations based on the hypothesis, but the creation of models typically happens before this stage. Choice D, conclusion, is the final step where scientists interpret the results and draw implications, making it an inappropriate step for creating a model.

4. Which cells myelinate neurons in the CNS?

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

Correct answer: D

Rationale: The correct answer is D, Oligodendrocytes. Oligodendrocytes are responsible for myelinating neurons in the central nervous system (CNS). Schwann cells, found in the peripheral nervous system, are responsible for myelinating neurons there. Astrocytes support and maintain the neuronal environment, while microglia function as immune cells in the CNS, participating in immune responses and cellular debris clearance. Therefore, choices A, B, and C are incorrect for myelination of CNS neurons.

5. What property of a substance remains constant regardless of changes in gravity?

• A. Mass
• B. Weight
• C. Volume
• D. Density

Correct answer: A

Rationale: Mass is a measure of the amount of matter in an object and remains constant regardless of changes in gravity. Weight, on the other hand, is a measure of the gravitational force acting on an object and varies with changes in gravity. Volume is the amount of space occupied by an object and can change with changes in gravity. Density is the mass of a substance per unit volume and can also change with changes in gravity if the volume changes. Therefore, the correct answer is mass as it remains the same regardless of the gravitational force acting on the object, making it an intrinsic property of the substance.

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