Question

how does a nerve impulse begin once a signal is received? a positive charge is created in the cell, which then travels down the rest of the cell. oxygen diffuses into the cell, which then reacts with ions in the cell. the cell fills with glucose, which gives it an energy surge.

Explanation:

When a neuron receives a signal, it triggers the opening of ion channels, allowing positively charged sodium ions to rush into the cell. This reverses the cell's resting negative charge, creating a positive charge (action potential) that propagates down the neuron's axon as a nerve impulse. The other options are incorrect: oxygen diffusion and glucose uptake support cellular energy needs but do not directly initiate a nerve impulse.

Answer:

A. A positive charge is created in the cell, which then travels down the rest of the cell.