Nursing Elites

1. Which molecules are soluble in nonpolar solvents but are hydrophobic?

• A. Carbohydrates
• B. Lipids
• C. Proteins
• D. Nucleic acids

Correct answer: B

Rationale: Lipids are hydrophobic molecules that are soluble in nonpolar solvents like oils but insoluble in water. They consist of fats, oils, waxes, and steroids and play essential roles in energy storage, insulation, and cell membrane structure. Carbohydrates, proteins, and nucleic acids are not typically soluble in nonpolar solvents and do not exhibit the same hydrophobic characteristics as lipids. Carbohydrates are usually hydrophilic and soluble in water, proteins have both hydrophilic and hydrophobic regions but are not generally soluble in nonpolar solvents, and nucleic acids are polar molecules that are not known for their solubility in nonpolar solvents.

2. Consider the graph representing a botanist's data on root growth. What is the independent variable?

• A. Temperature
• B. Root tissue
• C. Light exposure
• D. Root length

Correct answer: C

Rationale: The independent variable is the factor that is intentionally changed or manipulated by the researcher. In this case, light exposure is the independent variable because it is being controlled and tested to observe its effect on root growth. Choices A, B, and D are not the independent variable in this scenario. Temperature, root tissue, and root length are likely dependent variables that could be influenced by the changes in light exposure.

3. Which type of fiber is insoluble and promotes gut motility?

• A. Pectin
• B. Cellulose
• C. Beta-gluca
• D. Guar gum

Correct answer: B

Rationale: A) Pectin is a soluble fiber found in fruits and vegetables. It forms a gel-like substance in the gut and can help lower cholesterol levels. B) Cellulose is an insoluble fiber found in plants, particularly in the cell walls of fruits, vegetables, and whole grains. It adds bulk to the stool and promotes gut motility by aiding in the movement of food through the digestive system. C) Beta-glucan is a soluble fiber found in oats and barley. It can help lower cholesterol levels and improve blood sugar control. D) Guar gum is a soluble fiber derived from guar beans. It can help with digestion and may have a role in managing blood sugar levels. In this case, the question specifically asks for the type of fiber that is insoluble and promotes gut motility, which is characteristic of cellulose.

4. What are the four main types of macromolecules that are essential for life?

• A. Carbohydrates, lipids, proteins, and nucleic acids
• B. Carbohydrates, proteins, fats, and vitamins
• C. Minerals, vitamins, proteins, and fats
• D. Carbohydrates, lipids, proteins, and hormones

Correct answer: A

Rationale: The correct answer is A: Carbohydrates, lipids, proteins, and nucleic acids. These four types of macromolecules are essential for life as they serve crucial roles in various cellular processes. Carbohydrates are the primary energy source for cells and provide structural support. Lipids function as energy storage molecules and are essential components of cell membranes. Proteins have diverse functions in cellular processes, acting as enzymes, structural components, and more. Nucleic acids, like DNA and RNA, carry genetic information and are crucial for protein synthesis. Choices B, C, and D are incorrect because they include elements like fats, vitamins, minerals, and hormones, which are not the main types of macromolecules essential for life.

5. Which type of muscle tissue is found in the walls of blood vessels and helps regulate blood flow?

• A. Skeletal muscle
• B. Smooth muscle
• C. Cardiac muscle
• D. Striated muscle

Correct answer: B

Rationale: Smooth muscle is the correct answer. It is found in the walls of blood vessels and helps regulate blood flow by contracting and relaxing to adjust the diameter of the vessels. Skeletal muscle, found attached to bones, is responsible for voluntary movements and is not typically found in blood vessel walls. Cardiac muscle is specific to the heart and responsible for pumping blood, not found in blood vessel walls. Striated muscle, another term for skeletal muscle, is characterized by its striped appearance under a microscope but is not present in blood vessel walls.

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