Nursing Elites

1. Through which part of the digestive system are nutrients absorbed into the bloodstream?

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

Correct answer: C

Rationale: The small intestine is the primary site of nutrient absorption in the digestive system. It is where the majority of digestion and absorption of nutrients such as carbohydrates, proteins, and fats occurs. The inner lining of the small intestine is covered in tiny finger-like projections called villi, which increase the surface area available for absorption. Nutrients are absorbed through the walls of the small intestine and into the bloodstream to be transported to cells throughout the body. The stomach's main role is to break down food through the action of stomach acids and enzymes but does not absorb nutrients. The large intestine primarily absorbs water and electrolytes from the remaining indigestible food matter, and the esophagus is a muscular tube that transports food from the mouth to the stomach, without being involved in nutrient absorption.

2. The chemical equation below is unbalanced. When it is properly balanced, how many molecules of carbon dioxide (CO2) are produced for each molecule of propane (C3H8) in the reaction? 3C3H8 + 5O2 → 3CO2 + 4H2O

• A. One Half.
• B. Two.
• C. Three.
• D. Five.

Correct answer: B

Rationale: The balanced chemical equation for the combustion of propane is: 3C3H8 + 5O2 → 3CO2 + 4H2O. This equation shows that for every 3 molecules of propane (C3H8) consumed, 3 molecules of carbon dioxide (CO2) are produced. Therefore, when properly balanced, 3CO2 are produced for each molecule of propane used. Thus, the correct answer is B: Two. Choices A, C, and D are incorrect because they do not reflect the correct stoichiometry as determined by the balanced equation.

3. 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.

4. Which of the following correctly matches a category of protein with a physiological example?

• A. Keratin is a structural protein
• B. Antigens are hormonal proteins
• C. Channel proteins are marker proteins
• D. Actin is a transport protein

Correct answer: A

Rationale: Keratin is indeed a type of structural protein found in the skin, hair, and nails of animals. It provides strength and protection, helping to maintain the overall structure of these tissues. The other choices are incorrect as antigens are not hormonal proteins but rather are involved in immune response, channel proteins are involved in facilitating the transport of ions or molecules across cell membranes, and actin is primarily involved in cell structure and movement, not as a transport protein.

5. What is the term for a group of organisms with the same genetic makeup?

• A. Population
• B. Clone
• C. Genotype
• D. Species

Correct answer: B

Rationale: In this context, a clone (option B) is a group of organisms that are genetically identical because they are derived from a single ancestor. A population (option A) refers to a group of individuals of the same species living in the same area. Genotype (option C) refers to the genetic makeup of an individual organism. Species (option D) refers to a group of organisms that can interbreed and produce fertile offspring. Therefore, the most appropriate choice for the question is 'Clone,' as it specifically refers to organisms with the same genetic makeup.

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