This happens early in embryonic development in females, where one of the two X-Chromosomes is randomly (and permanently) inactivated, as you said, in cells other than egg cells.
This phenomonon is actually called X-Inactivation.
X-Inactivation make sure that females, just like males, have a single functional copy of the X Chromosome in each and every one of their cells in their body.
Glad I could help, byee now
Answer
The main reason being the amount of food available.
Explanation:
Think of it this way:
If an animal is trying to find food but another species is looking for the same prey then its going to be increasingly difficult for the species to find prey and if there's not enough of the prey species then the population of the predator to go down.
That is why its considered a limiting factor.
Answer: Composition maybe?
Explanation:
Very powerful microscopes were needed before cells could be observed in detail
