Nursing Elites

1. Which vitamin is produced when the skin is exposed to sunlight?

• A. Vitamin A
• B. Vitamin D
• C. Vitamin K
• D. Vitamin E

Correct answer: B

Rationale: Vitamin D is the correct answer. When the skin is exposed to sunlight, it triggers a process where a form of cholesterol in the skin is converted into vitamin D. This vitamin plays a crucial role in aiding calcium absorption in the gut, which is essential for maintaining strong and healthy bones. Vitamin A (Choice A) is important for vision and immune function but is not produced by sunlight exposure. Vitamin K (Choice C) is known for its role in blood clotting and bone metabolism, but it is not produced by sunlight. Vitamin E (Choice D) is an antioxidant that protects cells from damage but is not synthesized in the skin through sunlight exposure.

2. 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.

3. Which part of the male reproductive system is responsible for producing seminal fluid?

• A. Bladder
• B. Urethra
• C. Prostate gland
• D. Kidney

Correct answer: C

Rationale: The correct answer is the prostate gland (Choice C). The prostate gland, located near the bladder, is responsible for producing seminal fluid. This fluid, along with sperm from the testes, makes up semen. The bladder stores urine, the urethra is a tube that carries urine from the bladder out of the body, and the kidney filters waste from the blood to produce urine. The prostate gland's specific function is to secrete a milky, alkaline fluid that mixes with sperm during ejaculation to form semen. This fluid helps nourish and protect the sperm, aiding in their motility and viability. Therefore, the prostate gland plays a crucial role in male reproductive function by contributing to the composition and quality of semen, essential for fertility.

4. What is the name of the microscopic finger-like projections that increase the surface area for absorption in the small intestine?

• A. Goblet cells
• B. Paneth cells
• C. Villi
• D. Crypts of Lieberkühn

Correct answer: C

Rationale: A) Goblet cells: Goblet cells are specialized cells that secrete mucus to protect the lining of the digestive tract. While important for maintaining the health of the intestines, goblet cells do not increase the surface area for absorption in the small intestine. B) Paneth cells: Paneth cells are specialized cells found in the small intestine that secrete antimicrobial peptides. They play a role in protecting the intestinal stem cells and maintaining the gut microbiota balance, but they do not increase the surface area for absorption. C) Villi: Villi are microscopic finger-like projections found in the small intestine that increase the surface area available for absorption of nutrients. Each villus contains blood vessels and lacteals (lymphatic vessels) that help absorb nutrients from digested food. D) Crypts of Lieberkühn: Crypts of Lieberkühn are small pits located between the villi

5. Which level of protein structure is defined by the folds and coils of the protein's polypeptide backbone?

• A. Primary
• B. Secondary
• C. Tertiary
• D. Quaternary

Correct answer: B

Rationale: The correct answer is B: Secondary. The secondary structure of a protein is defined by the folds and coils of the protein's polypeptide backbone. This level of structure is characterized by the formation of alpha helices and beta sheets, which are stabilized by hydrogen bonds between amino acids along the polypeptide chain. Choice A, Primary, refers to the linear sequence of amino acids in the protein. Choice C, Tertiary, involves the 3D folding of the entire polypeptide chain. Choice D, Quaternary, pertains to the arrangement of multiple polypeptide subunits in a protein complex.

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