Answer:
If I am correct it is when the weaker individuals or mutated individuals are killed of by other predators or by nature. Because they cannot survive this is natural selection because they are killed of by nature. Then if they are weak their species will go extinct, thus they are naturally selected to die and only the strong species remain.
The x chromosomes are female chromosomes. We all start off as a female in the womb. Slowly through time, thr y chromosome jump in to make them a male and develop genes that woman do not have. For example, their beard gene is not necessary for example.
The correct answer is: Miami, Florida.
Polaris (other names are North Star or Pole Star) is one of the brightest, multiple star in the constellation of Ursa Minor. Because it is located nearly at the north celestial pole, it seems that the entire northern sky moves around it.
There are a few vital characteristics to mention here. First we have to know about which ions we're talking about as the cellular membrane is semi-permeable (lets some flow freely through the membrane and some not), it depends on the size of the compounds, and also the charge that a molecule has.