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 correct answer is B: Myelin sheath. The myelin sheath is a fatty substance that surrounds the axon of a neuron, acting as an insulator to speed up the transmission of nerve impulses. It does this by creating gaps called nodes of Ranvier where the nerve impulses jump from one node to the next, allowing for faster signal conduction. Dendrites are branch-like extensions that receive signals from other neurons, the synapse is the junction between two neurons where neurotransmitters are released, and the cell body contains the nucleus and organelles of the neuron, but it is the myelin sheath that specifically insulates and speeds up the transmission of nerve impulses along the axon.

2. During exercise, heart rate increases to deliver more oxygen to the body's tissues. What other cardiovascular response also increases?

• A. Blood pressure decreases
• B. Blood vessel diameter narrows
• C. Blood flow to muscles increases
• D. Blood viscosity thickens

Correct answer: A

Rationale: The correct answer is A: 'Blood pressure decreases.' When the heart rate increases during exercise to deliver more oxygen to the body's tissues, the blood pressure also tends to decrease. This is due to the enhanced efficiency of the heart in pumping blood, resulting in a lower pressure exerted on the blood vessel walls. In contrast, options B and D are incorrect as blood vessel diameter typically widens (dilates) during exercise to facilitate increased blood flow, and blood viscosity does not usually thicken during exercise. Option C is a distractor as blood flow to muscles indeed increases during exercise to meet the higher demand for oxygen and nutrients.

3. What property of a substance refers to its ability to undergo a chemical change and form new substances?

• A. Density
• B. Mass
• C. Reactivity
• D. Volume

Correct answer: c

Rationale: Reactivity refers to a substance's ability to undergo a chemical change or reaction, forming new substances with different properties.

4. What type of reaction is represented by the following equation: Fe2O3 (s) + 3H2 (g) -> 2Fe (s) + 3H2O (g)

• A. Combustion
• B. Decomposition
• C. Single displacement
• D. Redox reaction

Correct answer: D

Rationale: The given equation involves a transfer of electrons from iron oxide (Fe2O3) to hydrogen gas (H2), resulting in the formation of iron (Fe) and water (H2O). This transfer of electrons indicates a redox reaction, where oxidation and reduction occur simultaneously. In this case, iron is reduced from a higher oxidation state in Fe2O3 to a lower oxidation state in Fe, while hydrogen is oxidized from its elemental state in H2 to form water. Therefore, the correct answer is D: Redox reaction.

5. Which property of a wave represents the distance between two successive identical points on a wave?

• A. Wavelength
• B. Amplitude
• C. Frequency
• D. Period

Correct answer: a

Rationale: Wavelength is the distance between two identical points (like crests or troughs) on a wave.

6. The resolution of an optical instrument, like a microscope, refers to its ability to distinguish between:

• A. Different colors of light
• B. The presence or absence of light
• C. Variations in intensity
• D. Very close, nearly identical objects

Correct answer: D

Rationale: The resolution of an optical instrument, such as a microscope, is its ability to distinguish between very close, nearly identical objects. This means that the instrument can differentiate between two points that are close together and appear almost as one. A higher resolution allows for clearer and sharper images by minimizing the blurring effect that occurs when objects are close together. Options A, B, and C do not directly relate to the concept of resolution in optical instruments. Therefore, option D is the correct answer as it best describes what resolution entails in this context.

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