Nursing Elites

1. What is the primary function of ribosomes in the cell?

• A. To synthesize lipids and other cellular components
• B. To package and transport proteins
• C. To break down macromolecules
• D. To translate mRNA into proteins

Correct answer: D

Rationale: Ribosomes are cellular organelles responsible for protein synthesis. They read the genetic information encoded in messenger RNA (mRNA) and use this information to assemble amino acids into a specific sequence, forming a protein. This process is known as translation and is essential for the production of proteins that carry out various functions in the cell. Options A, B, and C are incorrect as they do not accurately describe the primary function of ribosomes. Choice A is incorrect because the synthesis of lipids and other cellular components is not the primary function of ribosomes. Choice B is incorrect as packaging and transporting proteins are functions typically associated with the endoplasmic reticulum and Golgi apparatus. Choice C is incorrect because ribosomes do not break down macromolecules; instead, they are involved in building proteins from amino acids.

2. Which term refers to a molecule of DNA and structural protein?

• A. Lysosome
• B. Centrosome
• C. Chromosome
• D. Genome

Correct answer: C

Rationale: The correct answer is C: Chromosome. A chromosome is a structure composed of DNA and proteins that carries genetic information. It is the condensed form of DNA associated with structural proteins, not just a molecule of DNA or protein. Lysosomes are membrane-bound organelles containing digestive enzymes, not DNA and protein. Centrosomes are involved in cell division, not related to DNA and protein together. A genome refers to an organism's complete set of DNA, not specifically a molecule containing both DNA and structural protein.

3. Which of the following statements regarding heart valves is correct?

• A. The atrioventricular valves lie between the atria and the ventricles.
• B. The pulmonary semilunar valve lies between the right ventricle and the pulmonary trunk.
• C. The atrioventricular valves prevent backflow into the atria when the ventricles contract.
• D. All of the above

Correct answer: D

Rationale: All of the statements are correct regarding heart valves. Choice A is accurate as the atrioventricular valves indeed lie between the atria and the ventricles. Choice B correctly identifies the location of the pulmonary semilunar valve. Choice C is true as the atrioventricular valves do prevent backflow into the atria during ventricular contraction. Therefore, selecting 'All of the above' as the correct answer is appropriate as all statements are accurate.

4. What is the process of breaking down proteins into amino acids called?

• A. Proteolysis
• B. Lipolysis
• C. Carbohydrate catabolism
• D. Nucleic acid catabolism

Correct answer: A

Rationale: Proteolysis is the specific process of breaking down proteins into amino acids. Lipolysis refers to the breakdown of fats into fatty acids and glycerol, not proteins. Carbohydrate catabolism involves the breakdown of carbohydrates into glucose for energy production, not proteins. Nucleic acid catabolism is the breakdown of nucleic acids into nucleotides, not proteins. Therefore, in the context of breaking down proteins into amino acids, the correct term is proteolysis.

5. Which radioactive isotope is commonly used in medical imaging techniques such as PET scans?

• A. Uranium-235
• B. Plutonium-239
• C. Potassium-40
• D. Fluorine-18

Correct answer: D

Rationale: Fluorine-18 is the radioactive isotope commonly used in medical imaging techniques such as PET scans. It is frequently used in the form of fluorodeoxyglucose (FDG) to locate areas of heightened metabolic activity in the body, such as in cancer cells. Uranium-235 and Plutonium-239 are not typically employed in medical imaging, and Potassium-40, while a naturally occurring radioactive isotope found in the human body, is not commonly used in medical imaging techniques.

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