Nursing Elites

1. Which part of the neuron insulates and speeds up the transmission of nerve impulses along the axon?

• A. Dendrite
• B. Myelin sheath
• C. Synapse
• D. Cell body

Correct answer: B

Rationale: The myelin sheath is a fatty layer that surrounds the axon of a neuron, providing insulation and speeding up the transmission of nerve impulses. This insulation helps prevent the loss of electrical signals as they travel along the axon, allowing for faster and more efficient communication within the nervous system. Dendrites are branching extensions of a neuron that receive signals from other neurons, the synapse is the junction between two neurons where communication occurs, and the cell body contains the nucleus and organelles of the neuron, but none of these structures provide insulation for the transmission of nerve impulses along the axon.

2. Which vitamin is essential for calcium absorption and bone health?

• A. Vitamin A
• B. Vitamin C
• C. Vitamin D
• D. Vitamin E

Correct answer: C

Rationale: Vitamin D is essential for calcium absorption in the intestines, which is crucial for maintaining strong and healthy bones. Without adequate vitamin D, the body cannot effectively absorb calcium, leading to weakened bones and an increased risk of fractures. Vitamin A (Choice A) is important for vision and immune function but is not directly involved in calcium absorption or bone health. Vitamin C (Choice B) is essential for collagen synthesis and immune function, but it does not play a direct role in calcium absorption or bone health. Vitamin E (Choice D) acts as an antioxidant and helps protect cells from damage, but it is not specifically required for calcium absorption or bone health. Therefore, the correct answer is Vitamin D as it is crucial for optimal bone health.

3. What type of reaction is represented by the following equation: 2C₆H₁₄ + 19O₂ → 12CO + 14H₂O?

• A. Substitution reaction
• B. Acid-base reaction
• C. Enzyme reaction
• D. Combustion reaction

Correct answer: D

Rationale: The given chemical equation represents a combustion reaction. Combustion reactions involve the burning of a hydrocarbon (C₆H₁₄) in the presence of oxygen (O₂) to produce carbon monoxide (CO) and water (H₂O). Combustion reactions typically release heat and light energy. In this case, the reactants are a hydrocarbon and oxygen, resulting in the formation of carbon monoxide and water. Choices A, B, and C are incorrect because the reaction does not involve substitution, acid-base reactions, or enzyme catalysis. Combustion reactions are characterized by the rapid combination of a substance with oxygen, leading to the production of heat and light energy.

4. Which type of bond is exemplified by KCl?

• A. Ionic bond
• B. Covalent bond
• C. Hydrogen bond
• D. Polar covalent bond

Correct answer: A

Rationale: KCl exemplifies an ionic bond. In an ionic bond, electrons are transferred between atoms, resulting in the formation of ions. In the case of KCl, potassium (K) donates an electron to chlorine (Cl), leading to the creation of K+ and Cl- ions, which are held together by electrostatic forces of attraction. Choice B, covalent bond, is incorrect because covalent bonds involve the sharing of electrons between atoms, not the transfer of electrons as seen in KCl. Choice C, hydrogen bond, is incorrect as hydrogen bonds are a type of intermolecular force, not a bond formed by the transfer or sharing of electrons between atoms. Choice D, polar covalent bond, is also incorrect because although it involves the sharing of electrons with an unequal distribution of charge, KCl is a clear example of ionic bonding where electrons are completely transferred.

5. Which organ produces insulin and glucagon?

• A. Salivary Glands
• B. Liver
• C. Gallbladder
• D. Pancreas

Correct answer: D

Rationale: The correct answer is D, Pancreas. The pancreas is the organ responsible for producing the hormones insulin and glucagon. Insulin functions to lower blood sugar levels by facilitating the uptake of glucose by cells for energy production. On the other hand, glucagon works to raise blood sugar levels by prompting the liver to release stored glucose into the bloodstream. The pancreas is a vital organ in the endocrine system, playing a crucial role in maintaining appropriate blood sugar levels in the body. Choices A, B, and C are incorrect as the salivary glands produce saliva, the liver is involved in various metabolic functions, and the gallbladder stores bile produced by the liver, but none of these organs produce insulin and glucagon.

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