Nursing Elites

1. Which part of the cell is responsible for storing genetic information?

• A. Ribosome
• B. Mitochondrion
• C. Nucleus
• D. Cytoplasm

Correct answer: C

Rationale: The correct answer is C, Nucleus. The nucleus is responsible for storing genetic information in the form of DNA. The DNA within the nucleus controls the activities of the cell by directing the synthesis of proteins and regulating gene expression. Choices A, Ribosome, B, Mitochondrion, and D, Cytoplasm, do not store genetic information. Ribosomes are involved in protein synthesis, mitochondria produce energy for the cell, and cytoplasm is a gel-like substance that houses organelles and where many cellular activities occur.

2. Which vitamin requires intrinsic factor for proper absorption?

• A. Vitamin A
• B. Vitamin C
• C. Vitamin D
• D. Vitamin B12

Correct answer: D

Rationale: Vitamin B12 requires intrinsic factor, a glycoprotein secreted by the parietal cells of the stomach, for proper absorption in the small intestine. Intrinsic factor binds to vitamin B12 and facilitates its absorption in the ileum. Deficiency in intrinsic factor can lead to pernicious anemia, a condition characterized by a lack of vitamin B12 absorption. Options A, B, and C are incorrect. Vitamin A is absorbed in the small intestine with the help of bile salts; Vitamin C is absorbed in the small intestine via active transport; Vitamin D is absorbed in the small intestine through a process involving bile salts and micelles. It is essential for students to understand this relationship as it highlights the importance of intrinsic factor in the absorption of specific vitamins and the consequences of its deficiency.

3. What term describes a series of muscle contractions that transports food down the digestive tract in a wave-like fashion?

• A. digestion
• B. deglutition
• C. defecation
• D. peristalsis

Correct answer: D

Rationale: Peristalsis is the correct term for the series of muscle contractions that move food down the digestive tract in a wave-like manner. This process helps propel food through the esophagus, stomach, and intestines, facilitating digestion and nutrient absorption. Digestion (Choice A) refers to the breakdown of food into smaller components, deglutition (Choice B) is the act of swallowing, and defecation (Choice C) is the elimination of waste from the body. Therefore, peristalsis is the most appropriate term to describe the described muscle contractions in the digestive system.

4. What tool helps scientists identify and classify organisms based on their shared characteristics?

• A. Binomial nomenclature
• B. Cladistics
• C. Dichotomous key
• D. Domain-based classification

Correct answer: C

Rationale: A) Binomial nomenclature is a system used to give each organism a two-part scientific name (genus and species) but does not help in identifying or classifying organisms based on shared characteristics. B) Cladistics is a method of classification based on evolutionary relationships and shared characteristics, but it is not a tool used for identifying organisms. C) A dichotomous key is a tool that helps scientists identify and classify organisms based on their shared characteristics by presenting a series of choices leading the user to the correct identification. D) Domain-based classification is a system of grouping organisms into three domains (Bacteria, Archaea, Eukarya) based on molecular and genetic similarities, but it is not a tool used for identifying organisms based on shared characteristics.

5. Which of the following units is used to express concentration as a mass of solute per unit volume of solution?

• A. Molality (m)
• B. Molarity (M)
• C. Weight percent (%)
• D. Parts per million (ppm)

Correct answer: A

Rationale: Molality (m) is the unit used to express concentration as a mass of solute per unit volume of solution. It is calculated by dividing the mass of solute in grams by the mass of the solvent in kilograms. Molality is preferred over molarity when there are large temperature variations as it is temperature-independent, making it a more accurate measure of concentration. Molarity (B) is the unit used to express concentration as moles of solute per liter of solution, weight percent (C) is the mass of solute per 100 parts of the total mass of the solution, and parts per million (D) is used to express very small concentrations where 1 ppm is equivalent to 1 mg of solute per liter of solution.

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