Nursing Elites

1. Which of the following structures is responsible for preventing the backflow of blood from the left ventricle into the left atrium?

• A. Aortic valve
• B. Pulmonary valve
• C. Tricuspid valve
• D. Mitral valve

Correct answer: D

Rationale: The correct answer is D, the Mitral valve. The mitral valve, also known as the bicuspid valve, is situated between the left atrium and the left ventricle. Its primary function is to prevent the backflow of blood from the left ventricle into the left atrium during ventricular contraction. The other choices are incorrect because: A) The aortic valve prevents backflow from the aorta into the left ventricle. B) The pulmonary valve prevents backflow from the pulmonary artery into the right ventricle. C) The tricuspid valve prevents backflow from the right ventricle into the right atrium.

2. What is the main role of the large intestine in digestion?

• A. Absorbing proteins
• B. Absorbing carbohydrates
• C. Absorbing fats
• D. Absorbing water

Correct answer: D

Rationale: The main role of the large intestine in digestion is to absorb water. When food reaches the large intestine, most nutrients have already been absorbed by the small intestine. In the large intestine, water is absorbed from the remaining undigested food, helping to form solid waste (feces). Absorbing proteins, carbohydrates, or fats primarily occurs in the small intestine, not in the large intestine. Therefore, options A, B, and C are incorrect.

3. Which of the following best describes one of the roles of RNA?

• A. Manufacturing the proteins needed from DNA
• B. Creating the bonds between the elements that make up DNA
• C. Sending messages about the correct sequence of proteins in DNA
• D. Forming the identifiable double helix shape of DNA

Correct answer: C

Rationale: The correct answer is C. RNA serves as a messenger that carries instructions from DNA for protein synthesis. It does not manufacture proteins directly from DNA (choice A), create bonds within DNA (choice B), or form the double helix structure of DNA (choice D). Therefore, the primary role of RNA is to convey information about the correct sequence of proteins to be synthesized based on the DNA sequences it receives.

4. Diabetes mellitus is a chronic condition affecting blood sugar control. What is the main type of hormone deficiency associated with type 1 diabetes?

• A. Insulin
• B. Glucagon
• C. Estrogen
• D. Testosterone

Correct answer: A

Rationale: The correct answer is A: Insulin. Type 1 diabetes is characterized by the body's inability to produce insulin, the hormone responsible for regulating blood sugar levels. Insulin deficiency in type 1 diabetes leads to high blood sugar levels as the body cannot effectively utilize glucose for energy. Glucagon (Choice B) is a hormone that works opposite to insulin, raising blood sugar levels. Estrogen (Choice C) and testosterone (Choice D) are not directly involved in blood sugar control or the pathophysiology of type 1 diabetes.

5. What is the length of DNA that can code for a particular protein?

• A. Chromosome
• B. Nucleotide
• C. Gene
• D. Ribosome

Correct answer: C

Rationale: The correct answer is C: Gene. A gene is a specific segment of DNA that contains the information necessary to produce a particular protein. Genes are responsible for coding proteins, and each gene carries the instructions for a specific protein. Chromosomes consist of many genes and are not a specific length that codes for a protein. Nucleotides are the building blocks of DNA and are not a length that codes for a protein. Ribosomes are cellular organelles involved in protein synthesis and do not directly code for proteins.

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