During the first 2-3 weeks you will not see any physical signs. Look at your dog's nipples, for if it is pink, that may be an indication. Be sure to observe your dog's body and it's weight.
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>
Let's go back to "Darwin's" evolution theory. mice can be smarter than the average hawk, they are fast, have underground protection from cold,heat, rain,ECT..and they scavenge during p.m. hours, not all hawks are nocturnal, that's why owls are nocturnal. This cycle ensures enough food source for all predators. A hawk can consume at least 6 mice per day/night. rodents are natural prey for all preditors., even coyote. hope this helps, plus mice reproduce quickly compared to preditors.
hope this helps..
<span>NA contains only elements, so it does not react easily. Many organisms do not contain DNA. Certain mutations in DNA happen at a constant rate. DNA does not change over time, making it a valuable clue.</span>
