Nursing Elites

1. Which of the following organelles is the site of cellular respiration?

• A. Nucleus
• B. Mitochondria
• C. Lysosomes
• D. Ribosomes

Correct answer: B

Rationale: The correct answer is B: Mitochondria. Mitochondria are known as the powerhouse of the cell because they generate most of the cell's supply of ATP through cellular respiration. The other organelles listed, such as the nucleus (choice A), lysosomes (choice C), and ribosomes (choice D), do not play a direct role in cellular respiration. The nucleus contains genetic material, lysosomes are involved in digestion and waste removal, and ribosomes are responsible for protein synthesis.

2. What is the difference between DNA and RNA?

• A. RNA has an extra Phosphate group
• B. DNA has one less oxygen than RNA
• C. RNA has one less oxygen than DNA
• D. DNA has an extra sugar molecule

Correct answer: B

Rationale: The correct answer is B. DNA has one less oxygen atom in its sugar molecule (deoxyribose) compared to RNA, which has a ribose sugar. Choice A is incorrect because RNA does not have an extra phosphate group. Choice C is incorrect as RNA actually has one more oxygen atom than DNA. Choice D is incorrect as DNA and RNA have different sugar molecules, with DNA having deoxyribose and RNA having ribose.

3. Which of the following options is the term used to represent alternative versions of a gene?

• A. Alleles
• B. Binary fission
• C. Heterozygous
• D. Homozygous

Correct answer: A

Rationale: The correct answer is A: Alleles. Alleles are different forms of a gene that can exist at a specific locus on a chromosome. They represent variations in a gene's DNA sequence. Choices B, C, and D are incorrect. Binary fission is a form of asexual reproduction in single-celled organisms, while heterozygous and homozygous refer to different combinations of alleles in an individual, not the alternative versions of a gene.

4. What is the most significant contributor to cellular function?

• A. Proteins
• B. Phospholipids
• C. Carbohydrates
• D. Fatty acids

Correct answer: A

Rationale: The correct answer is A: Proteins. Proteins are the most significant contributor to cellular function as they play crucial roles in almost all biological processes. They act as enzymes that catalyze reactions, are involved in cell signaling pathways, and provide structural support to cells. Phospholipids (Choice B), while important for cell membrane structure, do not have the same diverse functions as proteins in cellular processes. Carbohydrates (Choice C) primarily serve as an energy source and structural components but are not as versatile in cellular functions as proteins. Fatty acids (Choice D) are essential components of cell membranes and energy storage molecules but do not have the same broad range of functions as proteins in cellular processes.

5. Prophase is the first stage of mitosis. Which of the following best describes chromosomes during this stage?

• A. They are gathered on either side of the separating cell
• B. They are all aligned along the metaphase plate
• C. They are attached to the spindle
• D. They are visibly separate

Correct answer: D

Rationale: The correct answer is D. During prophase, the chromosomes condense and become visible as distinct structures under a microscope. Choice A is incorrect as chromosomes are not gathered on either side of the separating cell during prophase. Choice B is incorrect because chromosomes align along the metaphase plate during the subsequent stage, metaphase. Choice C is incorrect as chromosomes become attached to the spindle fibers during prometaphase, the stage following prophase.

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