Nursing Elites

1. What is the role of transfer RNA (tRNA) in protein synthesis?

• A. Transcribes DNA into mRNA
• B. Decodes the genetic code on mRNA
• C. Carries specific amino acids to the ribosomes
• D. Modifies the structure of proteins

Correct answer: C

Rationale: A) Transcribes DNA into mRNA: This is the function of RNA polymerase, not transfer RNA (tRNA). tRNA is involved in protein synthesis, not transcription. B) Decodes the genetic code on mRNA: This is the function of tRNA during translation. tRNA molecules carry specific amino acids and recognize the codons on mRNA, ensuring the correct amino acid is added to the growing polypeptide chain. C) Carries specific amino acids to the ribosomes: This is the primary role of tRNA in protein synthesis. Each tRNA molecule is specific for a particular amino acid and carries it to the ribosome, where it is added to the growing protein chain. D) Modifies the structure of proteins: This is not a function of tRNA. Protein modification can occur after translation is complete and involves other cellular processes and molecules.

2. Which structure in the respiratory system is responsible for gas exchange?

• A. Trachea
• B. Alveoli
• C. Bronchi
• D. Diaphragm

Correct answer: B

Rationale: The alveoli in the lungs are responsible for gas exchange. Alveoli have a rich blood supply and thin walls, enabling the exchange of oxygen and carbon dioxide. Oxygen diffuses into the blood from the alveoli, while carbon dioxide diffuses out. The trachea functions as an air passage, bronchi are the main airways into the lungs, and the diaphragm is the primary muscle involved in breathing by aiding in lung expansion and contraction, but they are not directly responsible for gas exchange like the alveoli.

3. Which type of muscle is responsible for moving the skeleton?

• A. Cardiac muscle
• B. Skeletal muscle
• C. Smooth muscle
• D. Voluntary muscle

Correct answer: B

Rationale: Skeletal muscle is the correct answer as it is responsible for moving the skeleton. Skeletal muscles are under voluntary control, meaning they can be consciously controlled by the individual. Cardiac muscle (Choice A) is found in the heart and is responsible for pumping blood, not moving the skeleton. Smooth muscle (Choice C) is found in internal organs and is responsible for involuntary movements like digestion. Voluntary muscle (Choice D) is not a specific type of muscle; it refers to muscles that can be consciously controlled, which includes skeletal muscles.

4. What is the term for the process of breaking a large molecule into smaller fragments by applying heat?

• A. Polymerization
• B. Hydrogenation
• C. Isomerization
• D. Pyrolysis

Correct answer: D

Rationale: Pyrolysis is the correct answer. It is the process of breaking down large molecules into smaller fragments by applying heat in the absence of oxygen. This results in the decomposition of molecules into simpler compounds. Polymerization, the process of synthesizing large molecules from smaller units, is incorrect as it is the opposite process. Hydrogenation involves adding hydrogen atoms to a compound, usually with a catalyst, which is not related to breaking down large molecules. Isomerization refers to rearranging atoms within a molecule to form isomeric compounds with the same molecular formula but different structural arrangements, which is also unrelated to the process described in the question.

5. Which of the following is NOT a method of sterilization?

• A. Autoclave
• B. UV light
• C. Chemical disinfectants
• D. Boiling water

Correct answer: D

Rationale: A) Autoclave: An autoclave is a method of sterilization that uses high pressure and steam to kill microorganisms, making it an effective way to sterilize equipment and materials.\nB) UV light: UV light is a method of sterilization that damages the DNA of microorganisms, preventing them from reproducing and causing infections.\nC) Chemical disinfectants: Chemical disinfectants are used to kill or inactivate microorganisms on surfaces, but they may not always achieve sterilization, which is the complete destruction of all microorganisms.\nD) Boiling water: Boiling water is a method of disinfection rather than sterilization. While boiling water can kill many microorganisms, it may not be effective against all types of bacteria, viruses, and spores, making it unsuitable for achieving sterilization.\n\nTherefore, the correct answer is D) Boiling water, as it is not a method of sterilization.

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