Nursing Elites

1. Which of the following nucleic acids carries amino acids to organelles called ribosomes, where the amino acids are linked one by one to produce a polypeptide?

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

Correct answer: D

Rationale: tRNA is the correct answer as it carries amino acids to the ribosomes during protein synthesis. Transfer RNA (tRNA) plays a crucial role in protein synthesis by bringing specific amino acids to the ribosome according to the mRNA sequence. Once at the ribosome, the amino acids are linked together to form a polypeptide chain. This process is essential for the creation of proteins in the cell, highlighting the significance of tRNA in the translation process. Choice A, DNA, is incorrect as DNA does not directly participate in protein synthesis. Choice B, mRNA, is incorrect as mRNA carries the genetic information from DNA to the ribosome but does not directly carry amino acids. Choice C, rRNA, is incorrect as ribosomal RNA is a component of the ribosome structure and is involved in protein synthesis but does not carry amino acids like tRNA.

2. What is the scientific study of the relationships between organisms and their environment?

• A. Zoology
• B. Botany
• C. Ecology
• D. Genetics

Correct answer: C

Rationale: Ecology is the scientific study of the relationships between organisms and their environment, including the interactions between living organisms and their physical surroundings. This field focuses on how organisms interact with each other and their environment. Zoology is the study of animals, Botany is the study of plants, and Genetics is the study of genes and heredity, which are not directly related to the relationships between organisms and their environment. Therefore, the correct answer is Ecology as it specifically deals with the interactions between living organisms and their environment.

3. Which type of reaction is represented by the equation A + B → AB?

• A. Synthesis
• B. Decomposition
• C. Single Replacement
• D. Double Replacement

Correct answer: A

Rationale: The correct answer is 'Synthesis.' In a synthesis reaction, two or more reactants combine to form a single product. The equation A + B → AB represents a synthesis reaction where substances A and B combine to form compound AB. Choice B, 'Decomposition,' involves a single compound breaking down into two or more simpler substances, which is not the case in this equation. Choices C and D, 'Single Replacement' and 'Double Replacement,' involve the replacement of elements in compounds or the exchange of ions between compounds, neither of which is depicted in the given equation. Thus, 'Synthesis' is the most suitable classification for the reaction A + B → AB.

4. Which of the following describes a situation in which research results are consistent with every subsequent experiment, but the test used in the experiment does not measure what it claims to measure?

• A. reliable, but not valid
• B. valid, but not reliable
• C. neither reliable nor valid
• D. both reliable and valid

Correct answer: A

Rationale: The correct answer is A, 'reliable, but not valid.' In this scenario, the research results are consistent in every subsequent experiment, indicating reliability. However, the test used does not measure what it claims to measure, leading to a lack of validity in the results. Choice B, 'valid, but not reliable,' would imply that the test consistently measures what it claims but the results are not consistent, which is not the case here. Choice C, 'neither reliable nor valid,' would suggest that the results are neither consistent nor relevant, which does not align with the provided scenario. Choice D, 'both reliable and valid,' would mean that the results are consistent and measure what they claim to measure, which contradicts the situation described in the question.

5. Why are elements in Group 18 (Noble gases) generally unreactive?

• A. They have high atomic masses
• B. They lack valence electrons
• C. Their outermost electron shells are completely filled
• D. They exist as single atoms, not molecules

Correct answer: C

Rationale: Elements in Group 18 (Noble gases) are generally unreactive because their outermost electron shells are completely filled. This results in high stability and low reactivity since they have achieved a full valence shell configuration, making them less likely to gain, lose, or share electrons with other atoms. The full valence shell configuration leads to a minimal tendency for these elements to form chemical bonds, hence exhibiting low reactivity. Choices A, B, and D are incorrect because high atomic masses, lack of valence electrons, and existing as single atoms do not directly contribute to the unreactivity of noble gases. It is the full valence shell configuration that is the primary reason for their inert nature.

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