Nursing Elites

1. Which of the following describes the flow of genetic information from DNA to protein?

• A. Replication
• B. Transcription
• C. Translation
• D. Both transcription and translation

Correct answer: D

Rationale: The correct answer is D, 'Both transcription and translation.' Genetic information flows from DNA to RNA through transcription and from RNA to protein through translation. Replication is the process of copying DNA to produce an identical DNA molecule. Choice A, 'Replication,' is incorrect because replication is not directly involved in the flow of genetic information from DNA to protein. Choice B, 'Transcription,' is incorrect as it represents the process of synthesizing RNA from a DNA template, which is the initial step in the flow of genetic information. Choice C, 'Translation,' is also incorrect as it refers to the process of translating the information in mRNA into a sequence of amino acids during protein synthesis, which is the second step in the flow of genetic information.

2. Which feedback loops are less common and sometimes harmful because they enhance stimuli rather than inhibit them?

• A. Negative feedback loop
• B. Positive feedback loop
• C. Inhibitory feedback loop
• D. Stimulating feedback loop

Correct answer: B

Rationale: Correct. Positive feedback loops enhance or amplify changes, which can sometimes be harmful as they drive processes further from equilibrium. In contrast, negative feedback loops work to counteract deviations from a set point, promoting stability. Choice A, 'Negative feedback loop,' is incorrect because negative feedback loops inhibit or reduce changes, promoting stability. Choice C, 'Inhibitory feedback loop,' is incorrect as it is synonymous with negative feedback loops. Choice D, 'Stimulating feedback loop,' is incorrect as it inaccurately describes the nature of positive feedback loops.

3. Which of the following substances is a common base found in household products?

• A. Sodium chloride (NaCl)
• B. Ammonia (NH₃)
• C. Vinegar
• D. Lemon juice

Correct answer: B

Rationale: The correct answer is B, Ammonia (NH₃). Ammonia is commonly found in household products and is used in cleaning agents due to its alkaline properties. Sodium chloride (NaCl) is a common salt and not a base. Vinegar is acetic acid, which is acidic in nature. Lemon juice contains citric acid, making it acidic as well. Therefore, ammonia is the only base among the choices provided.

4. The term 'symbiotic relationship' describes an interaction between two organisms where:

• A. One organism benefits and the other is unaffected
• B. Both organisms are harmed by the interaction
• C. One organism benefits and the other is negatively impacted
• D. Both organisms benefit from the interaction

Correct answer: D

Rationale: In a symbiotic relationship, both organisms involved benefit from the interaction. This mutually beneficial relationship can take different forms, such as mutualism where both organisms benefit, commensalism where one organism benefits and the other is unaffected, or parasitism where one organism benefits at the expense of the other. In this case, the term 'symbiotic relationship' specifically refers to a scenario where both organisms derive some form of benefit from their interaction. Choices A, B, and C are incorrect because they do not accurately describe a symbiotic relationship. In symbiosis, both organisms benefit, making option D the correct choice.

5. What is the primary function of the CRISPR-Cas9 system in gene editing?

• A. To amplify specific DNA sequences.
• B. To cut DNA at specific locations.
• C. To deliver genes into cells.
• D. To sequence entire genomes.

Correct answer: B

Rationale: The CRISPR-Cas9 system is a powerful tool used in gene editing to precisely target and cut DNA at specific locations within the genome. This system consists of a guide RNA that directs the Cas9 enzyme to the desired DNA sequence, where it creates a double-strand break. This break can then be repaired by the cell's natural DNA repair mechanisms, allowing for the introduction of specific genetic modifications. Options A, C, and D are incorrect as they do not accurately describe the primary function of the CRISPR-Cas9 system in gene editing. Amplifying DNA sequences, delivering genes into cells, and sequencing entire genomes are not the main functions of the CRISPR-Cas9 system, which is primarily focused on precise DNA cutting for targeted genetic modifications.

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