The Outside of a Neuron Is Positively Charged at Resting

question 67

Multiple Choice

The outside of a neuron is positively charged at resting potential.Why do K⁺ ions leave the cell when K⁺ channels open during an action potential?

• A)The diffusion gradient is the only factor that affects ion movement.
• B)K⁺ ions are actively pumped out by the sodium-potassium pump acting in reverse.
• C)Voltage-gated K+ channels open when membrane potential reaches +50 mV during the depolarization phase.The diffusion gradient and electrical force cooperate to drive K+ ions out of the cell.
• D)Negatively charged proteins leave the cell at the onset of the action potential.

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Definitions:

Carbon Dioxide

A colorless, odorless gas produced by burning carbon and organic compounds and by respiration. It is naturally present in air and is absorbed by plants in photosynthesis.

Animals

Multicellular, eukaryotic organisms of the kingdom Animalia that are characterized by their ability to move, reproduce sexually, and consume organic material.

Major Lineage

A principal branch or group in the evolutionary tree that represents a large division of organisms sharing a common ancestor.

Fungi

A kingdom of organisms that includes yeasts, molds, and mushrooms; characterized by their absorption of food and importance in ecological and human health.