The normal membrane potential inside the axon of nerve cells is –70mV, and since this potential can change in nerve cells it is called the resting potential. When a stimulus is applied a brief reversal of the membrane potential, lasting about a millisecond, occurs. This brief reversal is called the action potential
<span>A stimulus can cause the membrane potential to change a little. The voltage-gated ion channels can detect this change, and when the potential reaches –30mV the sodium channels open for 0.5ms. The causes sodium ions to rush in, making the inside of the cell more positive. This phase is referred to as a depolarisation since the normal voltage polarity (negative inside) is reversed (becomes positive inside). </span>
<span>Repolarisation. At a certain point, the depolarisation of the membrane causes the sodium channels to close. As a result the potassium channels open for 0.5ms, causing potassium ions to rush out, making the inside more negative again. Since this restores the original polarity, it is called repolarisation. As the polarity becomes restored, there is a slight ‘overshoot’ in the movement of potassium ions (called hyperpolarisation). The resting membrane potential is restored by the Na+K+ATPase pump.</span>
Here are the reason why joining flocks will increase their chance of survival:
- Protection from predator
Their predator (such as falcons) can only get one bird at a time. Joining a flock will reduce their chance of being caught because they are moving in large unstoppable mass.
- Conserving heat
Being around the flock will help them maintain their body temperature to survive a harsh winter.
1. wear safety glasses
2.never touch heating source
3. keep away from overhead shelving
Answer:
The answer is prokaryotes
