Nursing Elites

1. What is the myelin sheath and what does it do?

• A. A group of nerve cells that perform a specific function.
• B. A fatty substance that insulates some nerve fibers.
• C. A fluid-filled cavity within the brain.
• D. The junction between two neurons.

Correct answer: B

Rationale: The myelin sheath is a fatty substance that insulates some nerve fibers. It is made up of specialized cells that wrap around the axons of neurons, providing insulation and speeding up the transmission of nerve impulses. Choice A is incorrect as the myelin sheath is not a group of nerve cells but rather a substance that surrounds nerve fibers. Choice C is incorrect as the myelin sheath is not a fluid-filled cavity within the brain. Choice D is incorrect as the myelin sheath is not the junction between two neurons.

2. What function do hydrophobic proteins often provide in the body?

• A. Digestive enzymes
• B. Provide structure
• C. Carry oxygen molecules
• D. Store energy

Correct answer: B

Rationale: Hydrophobic proteins are known for their ability to repel water and are often involved in providing structural support in cells and tissues. They help maintain the structural integrity and shape of cell membranes, organelles, and other cellular components. Choice A, digestive enzymes, typically consist of hydrophilic proteins that interact with water and substrates to facilitate digestion. Choice C, carrying oxygen molecules, is a function commonly associated with specific proteins like hemoglobin. Choice D, storing energy, is usually performed by proteins like enzymes involved in energy storage and release, such as glycogen phosphorylase.

3. A child complains of heavy breathing even when relaxing. They are an otherwise healthy child with no history of respiratory problems. What might be the issue?

• A. Asthma
• B. Blood clot
• C. Hyperventilation
• D. Exercising too hard

Correct answer: C

Rationale: In this scenario, where a child complains of heavy breathing even when relaxing and has no history of respiratory problems, the most likely issue is hyperventilation. Hyperventilation is an abnormal breathing pattern where a person breathes in excess of the body's requirements. It can be triggered by stress, anxiety, panic attacks, or lower-than-normal carbon dioxide levels in the blood. Unlike asthma, a blood clot, or exercising too hard, hyperventilation fits the symptoms described and is more common in individuals without a history of respiratory problems.

4. Which of the following is NOT a risk factor for developing atherosclerosis?

• A. High blood pressure
• B. High levels of LDL cholesterol
• C. Regular physical activity
• D. Smoking

Correct answer: C

Rationale: Regular physical activity is not a risk factor for developing atherosclerosis; in fact, it is associated with a reduced risk. High blood pressure, high levels of LDL cholesterol, and smoking are all known risk factors for atherosclerosis. Regular physical activity plays a crucial role in improving cardiovascular health, reducing the risk of atherosclerosis, and maintaining overall well-being. Therefore, the correct answer is regular physical activity (choice C).

5. Which of the following is unique to covalent bonds?

• A. Most covalent bonds are formed between the elements H, F, N, and O.
• B. Covalent bonds are dependent on forming dipoles.
• C. Bonding electrons are shared between two or more atoms.
• D. Molecules with covalent bonds tend to have a crystalline solid structure.

Correct answer: C

Rationale: The correct answer is C: 'Bonding electrons are shared between two or more atoms.' This statement is unique to covalent bonds. In covalent bonds, atoms share electrons to achieve a stable electron configuration, which leads to the formation of a bond. This sharing of electrons is a fundamental characteristic of covalent bonds and distinguishes them from other types of chemical bonds, such as ionic bonds, where electrons are transferred rather than shared. Choices A, B, and D do not represent unique characteristics of covalent bonds. Choice A describes some common elements involved in covalent bonds, choice B refers to the concept of dipoles, which can also exist in other types of bonds, and choice D describes a property of molecules (crystalline solid structure) that is not exclusive to covalent bonds.

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