Nursing Elites

1. What is the process by which RNA molecules are modified after transcription but before translation?

• A. Replication
• B. Splicing
• C. Editing
• D. Packaging

Correct answer: B

Rationale: B) Splicing is the correct answer. Splicing is the process by which non-coding regions (introns) are removed from pre-mRNA, and the remaining coding regions (exons) are joined together to form mature mRNA. This modification occurs after transcription but before translation. A) Replication is incorrect as replication is the process by which DNA is copied to produce a new DNA molecule, not RNA modifications. C) Editing may involve RNA editing, but it is not commonly used to describe the modification of RNA molecules after transcription. D) Packaging is not the correct term as it refers to the condensation and organization of DNA into chromatin in eukaryotic cells, not the modification of RNA molecules.

2. What is the difference between mitosis and meiosis?

• A. Mitosis produces haploid cells, while meiosis produces diploid cells
• B. Mitosis involves crossing over, while meiosis does not.
• C. Mitosis results in four daughter cells, while meiosis results in two
• D. Mitosis is responsible for sexual reproduction, while meiosis is responsible for asexual reproduction.

Correct answer: C

Rationale: - Mitosis is a type of cell division that results in two identical daughter cells with the same number of chromosomes as the parent cell. Therefore, mitosis results in two daughter cells. - Meiosis is a type of cell division that results in four daughter cells, each with half the number of chromosomes as the parent cell. This reduction in chromosome number is essential for sexual reproduction. - Option A is incorrect because mitosis produces diploid cells (cells with the same number of chromosomes as the parent cell), while meiosis produces haploid cells (cells with half the number of chromosomes as the parent cell). - Option B is incorrect because crossing over, the exchange of genetic material between homologous chromosomes, occurs during meiosis and not during mitosis. - Option D is incorrect because mitosis is not responsible for sexual reproduction; it is a process of asexual reproduction and

3. Melatonin is a hormone produced by the pineal gland. What is its primary function?

• A. Regulate blood pressure
• B. Stimulate the digestive system
• C. Control sleep-wake cycles
• D. Maintain bone density

Correct answer: C

Rationale: Melatonin is primarily known for its role in controlling sleep-wake cycles. It is produced by the pineal gland in response to darkness, helping signal the body that it is time to sleep. Melatonin levels typically rise in the evening and stay elevated throughout the night, promoting sleep. Choices A, B, and D are incorrect as melatonin's primary function is not to regulate blood pressure, stimulate the digestive system, or maintain bone density. While melatonin may have some indirect effects on these functions, its main role lies in regulating the circadian rhythm and promoting a restful sleep cycle.

4. A person wakes up with a fever. The body begins its response to locate the origin of the problem and fix it. What type of feedback mechanism is this?

• A. Equal
• B. Negative
• C. Neutral
• D. Positive

Correct answer: B

Rationale: This scenario describes a negative feedback mechanism. When the body detects a fever, it initiates responses to lower the temperature back to normal levels. Negative feedback mechanisms work to counteract changes and maintain homeostasis in the body. Choice A ('Equal') is incorrect as feedback mechanisms aim to restore balance, not maintain an equal state. Choice C ('Neutral') is incorrect as it does not describe the corrective nature of negative feedback. Choice D ('Positive') is incorrect as it would amplify the fever rather than regulate it.

5. During antibiotic use, bacteria can evolve resistance. This is an example of:

• A. Coevolution (two species influencing each other's evolution)
• B. Convergent evolution (unrelated organisms evolving similar traits)
• C. Macroevolution (large-scale evolutionary change)
• D. Artificial selection acting on a natural process

Correct answer: D

Rationale: The process of bacteria evolving resistance to antibiotics due to the selective pressure exerted by the antibiotics is an example of artificial selection (human intervention selecting for certain traits) acting on a natural process (bacterial evolution). Antibiotic use creates a selective pressure that favors the survival and reproduction of bacteria with resistance traits, leading to the evolution of antibiotic-resistant strains. - Coevolution (option A) refers to the influence of two species on each other's evolution, which is not the case in the scenario described in the question. - Convergent evolution (option B) involves unrelated organisms evolving similar traits due to similar environmental pressures, which is not directly applicable to the situation of bacteria evolving resistance to antibiotics. - Macroevolution (option C) refers to large-scale evolutionary changes over long periods, which is not specifically demonstrated in the context of bacteria evolving resistance during antibiotic use.

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