Nursing Elites

1. Which of the following nucleic acids carries the genetic information copied from DNA to the ribosomes?

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

Correct answer: B

Rationale: The correct answer is B: mRNA. Messenger RNA (mRNA) is responsible for carrying the genetic information copied from DNA to the ribosomes for protein synthesis. mRNA serves as a temporary copy of the genetic instructions stored in DNA and acts as a messenger between the nucleus and ribosomes in the cytoplasm where protein synthesis occurs. While rRNA (ribosomal RNA) and tRNA (transfer RNA) play essential roles in the process of translation at the ribosomes, mRNA is the nucleic acid directly involved in carrying the genetic code for protein synthesis. Therefore, choices A, C, and D are incorrect as DNA is the original genetic material, rRNA is a component of the ribosomes, and tRNA carries amino acids during protein synthesis, respectively.

2. In a single displacement reaction, one element takes the place of another element in a compound. Which of the following is an example?

• A. 2H2 + O2 -> 2H2O
• B. Zn + 2HCl -> ZnCl2 + H2
• C. CaCO3 -> CaO + CO2
• D. CH4 + 2O2 -> CO2 + 2H2O

Correct answer: B

Rationale: Option B demonstrates a single displacement reaction where zinc (Zn) displaces hydrogen (H) in hydrochloric acid (HCl) to produce zinc chloride (ZnCl2) and hydrogen gas (H2). This reaction exemplifies the concept of one element (Zn) replacing another element (H) in a compound (HCl), which is characteristic of single displacement reactions. Choices A, C, and D do not involve a single element displacing another in a compound, making them incorrect. In choice A, hydrogen and oxygen combine to form water, which is not a single displacement reaction. In choice C, calcium carbonate decomposes into calcium oxide and carbon dioxide, not involving displacement of elements. In choice D, methane reacts with oxygen to form carbon dioxide and water, which is a combustion reaction, not a single displacement reaction.

3. What are the four main types of macromolecules that are essential for life?

• A. Carbohydrates, lipids, proteins, and nucleic acids
• B. Carbohydrates, proteins, fats, and vitamins
• C. Minerals, vitamins, proteins, and fats
• D. Carbohydrates, lipids, proteins, and hormones

Correct answer: A

Rationale: The correct answer is A: Carbohydrates, lipids, proteins, and nucleic acids. These four types of macromolecules are essential for life as they serve crucial roles in various cellular processes. Carbohydrates are the primary energy source for cells and provide structural support. Lipids function as energy storage molecules and are essential components of cell membranes. Proteins have diverse functions in cellular processes, acting as enzymes, structural components, and more. Nucleic acids, like DNA and RNA, carry genetic information and are crucial for protein synthesis. Choices B, C, and D are incorrect because they include elements like fats, vitamins, minerals, and hormones, which are not the main types of macromolecules essential for life.

4. Which property of a substance refers to its ability to be stretched into thin wires without breaking?

• A. Conductivity
• B. Viscosity
• C. Ductility
• D. Malleability

Correct answer: C

Rationale: Ductility is the property of a substance that allows it to be stretched into thin wires without breaking. This property is distinct from the other options provided. Conductivity refers to the ability to conduct electricity or heat, viscosity refers to a liquid's resistance to flow, and malleability refers to the ability of a substance to be hammered or rolled into thin sheets. Therefore, the correct answer is 'Ductility.'

5. What is the role of the pancreas in the digestive system?

• A. To store bile
• B. To secrete digestive enzymes
• C. To digest proteins
• D. To absorb nutrients

Correct answer: B

Rationale: The correct answer is B: 'To secrete digestive enzymes.' The pancreas plays a crucial role in the digestive system by secreting digestive enzymes that aid in breaking down food in the small intestine. These enzymes help in the digestion of carbohydrates, fats, and proteins, facilitating the absorption of nutrients from the digested food. Choice A is incorrect because the pancreas is not responsible for storing bile; the gallbladder stores bile. Choice C is incorrect because the pancreas secretes enzymes for protein digestion but does not digest proteins itself. Choice D is incorrect as the absorption of nutrients primarily occurs in the small intestine, not in the pancreas.

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