A vague question, but let me try to explain. My friend explained to me that in females, some cells use one X chromosome, while all others use the other X chromosome. This can result in some differences of appearance of certain individuals. The Wikipedia page on X-inactivation shows an example. There is a picture there that shows a cat with fur of two colors, each showing in seemingly random groups. My friend had explained that when one cell "deactivates" its X chromosome, all of its descendants have the same deactivated X chromosome, so it makes sense that the similar colors appear in groups on the cat's coat.
But it seems tigers' coats are much more complicated than that. The pattern on a tiger's coat is not completely random. They make very discernible shapes. There are clear borders inside which only black fur grows, and outside of which only orange fur grows. How is this possible?
I'm not suggesting that the patters on tigers' fur is in any way related to X-inactivation, since I know that only applies to female mammals. But X-inactivation seems like a "natural" phenomenon, while the stripes on a tiger (or other animals with complex patters) seem a bit more bizarre. How do the cells on a tiger's body know which color to show and still follow the pattern?