Nursing Elites

1. Which is not part of a nucleic acid?

• A. Sulfate
• B. Phosphate
• C. Carbon
• D. Nitrogen

Correct answer: A

Rationale: Sulfate is not part of a nucleic acid. Nucleic acids, such as DNA and RNA, are composed of nucleotide units, which consist of a phosphate group, a sugar molecule (ribose in RNA and deoxyribose in DNA), and a nitrogenous base. Carbon and nitrogen are essential elements found in nucleic acids, while sulfate is not a component of nucleic acid structure. Therefore, the correct answer is A: Sulfate.

2. Genes control heredity in man and other organisms. This gene is ___

• A. A segment of DNA
• B. A bead-like structure on the chromosomes
• C. A protein molecule
• D. A segment of RNA

Correct answer: A

Rationale: Genes are sections of DNA that contain instructions for building and operating living organisms. These sections of DNA contain the genetic information that is passed on from one generation to the next. Genes are composed of specific sequences of nucleotides within the DNA molecule. Therefore, genes are best described as segments of DNA. Choice A is correct. Choice B is incorrect because genes are not bead-like structures on chromosomes but specific sequences of DNA. Choice C is incorrect because genes are not protein molecules but rather sequences of nucleotides. Choice D is incorrect because genes are not segments of RNA but DNA.

3. What is represented by this formula: 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂?

• A. Glycolysis
• B. Cellular respiration
• C. Photosynthesis
• D. Electronic transport

Correct answer: C

Rationale: The formula represents the process of photosynthesis, where carbon dioxide (CO₂) and water (H₂O) are converted into glucose (C₆H₁₂O₆) and oxygen (O₂) using light energy. This process is essential for plants and some microorganisms to produce food and oxygen. Glycolysis and cellular respiration involve breaking down glucose to produce energy, and the electron transport chain is part of cellular respiration, not photosynthesis.

4. During which phase of cell division do the chromosomes replicate?

• A. Prophase
• B. Interphase
• C. Anaphase
• D. Telophase

Correct answer: B

Rationale: Chromosomes replicate during the interphase of the cell cycle. Interphase is the phase where the cell prepares for division by undergoing various activities such as growth, DNA replication, and protein synthesis. During DNA replication in interphase, each chromosome in the cell is duplicated to form two sister chromatids, which are then separated during cell division. Prophase is the phase where the chromosomes condense, and the nuclear envelope breaks down. Anaphase is the phase where sister chromatids are pulled apart towards opposite poles of the cell. Telophase is the phase where the nuclear envelope reforms, and chromosomes begin to decondense.

5. During which phase is the chromosome number reduced from diploid to haploid?

• A. S phase
• B. interphase
• C. mitosis
• D. meiosis I

Correct answer: D

Rationale: The correct answer is 'meiosis I.' During meiosis I, the chromosome number is reduced from diploid to haploid through two rounds of division. Choice A ('S phase') is incorrect as the S phase is part of the cell cycle where DNA is replicated. Choice B ('interphase') is also incorrect as interphase is the phase where the cell prepares for division. Choice C ('mitosis') is incorrect as mitosis is a process where a diploid cell divides to produce two identical diploid daughter cells, maintaining the chromosome number.

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