Answer:
The first bullet point is correct
Explanation:
The cell membrane controls what comes in and out of the cell, it needs minerals so would not block them completely, and water does not enter cells so it is clearly the first one.
<h2>Sodium channels </h2>
Explanation:
Depolarization is a result of sodium channels opening as a result of chemical or pressure-based stimuli
- Depolarization starts when a threshold stimulus applied on a neuron via Na+ mechanically operated channels that trigger action potential
- Action potential is an efficient signaling process by which distantly located cells communicate to each other
- Depolarization of membrane potential is due to influx of Na+ via voltage gated Na+ channels
- Fast opening of voltage gated Na+ channel shifts membrane potential from -70mV to + 50mV at which voltage gated Na+ channels become inactive thus influx of Na+ abruptly stops
A major problem in sending space probes to Jupiter is that the planet has no solid surface on which to land, as there is a smooth transition between the planet's atmosphere and its fluid interior. Any probes descending into the atmosphere are eventually crushed by the immense pressures within Jupiter
