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. Which of the following components of the human integumentary system is the deepest?

• A. Stratum basale
• B. Epidermis
• C. Hypodermis
• D. Dermis

Correct answer: C

Rationale: The hypodermis is the deepest layer of the integumentary system, located below the dermis. It serves as a layer of fat that helps insulate the body, store energy, and provide cushioning. The stratum basale is the deepest layer of the epidermis, not the entire integumentary system. The epidermis is the outermost layer of the skin, followed by the dermis, and then the hypodermis. Therefore, the correct answer is the hypodermis (choice C). Choices A, B, and D are incorrect as they do not represent the deepest layer of the integumentary system.

3. Where does most of the chemical digestion take place?

• A. Large intestine
• B. Stomach
• C. Small intestine
• D. Esophagus

Correct answer: C

Rationale: Most of the chemical digestion occurs in the small intestine. Enzymes in the small intestine break down nutrients into smaller molecules that can be absorbed by the body. The stomach plays a role in digestion by breaking down food mechanically and initiating some chemical digestion, but the majority of nutrient breakdown and absorption happens in the small intestine. The large intestine mainly absorbs water and salts, with little to no digestion taking place there. The esophagus is a muscular tube that helps move food from the mouth to the stomach and does not participate in digestion.

4. What is the main function of peroxisomes in the cell?

• A. To break down hydrogen peroxide
• B. To synthesize lipids and other cellular components
• C. To package and transport proteins
• D. To store genetic material

Correct answer: A

Rationale: Peroxisomes are membrane-bound organelles found in eukaryotic cells that contain enzymes involved in various metabolic processes. One of the main functions of peroxisomes is to break down hydrogen peroxide, a toxic byproduct of metabolism, into water and oxygen through the action of the enzyme catalase. This process helps protect the cell from oxidative damage caused by hydrogen peroxide. While peroxisomes are involved in other metabolic functions such as lipid metabolism and the synthesis of bile acids, their primary role is the breakdown of hydrogen peroxide. Choices B, C, and D are incorrect because peroxisomes are not primarily responsible for synthesizing lipids, packaging and transporting proteins, or storing genetic material within the cell.

5. What are the differences between RNA and DNA?

• A. Both have the same structure and function.
• B. RNA is single-stranded, while DNA is double-stranded.
• C. RNA contains ribose sugar, while DNA contains deoxyribose sugar.
• D. RNA has adenine and guanine, while DNA has thymine and cytosine.

Correct answer: B

Rationale: A) This statement is incorrect. RNA and DNA have different structures and functions. RNA is involved in protein synthesis and other cellular processes, while DNA stores genetic information. B) This statement is correct. RNA is typically single-stranded, while DNA is double-stranded, forming a double helix structure. C) This statement is correct. RNA contains ribose sugar in its backbone, while DNA contains deoxyribose sugar. D) This statement is incorrect. RNA contains adenine, guanine, cytosine, and uracil, while DNA contains adenine, guanine, cytosine, and thymine. Choice B is the correct answer as it accurately describes one of the key differences between RNA and DNA, emphasizing their structural disparity in terms of single-strandedness for RNA and double-strandedness for DNA. Choices A, C, and D contain inaccuracies regarding the structural and compositional distinctions between RNA and DNA, making them incorrect choices.

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