"So is first there are chickens , and is chicken-egg."

I don't agree. If you follow Darwinism then it's likely that chickens evolved out of other type of birds. So at a certain point the bird evolved genetically and at that point it was considered to be a chicken.

Genetic rearranging happens before an animal is born, not after. So first came the egg, because it was already a chicken. For it to grow up didn't make it more chicken then it already was.

It's the same like a baby is not less human then a grown up. Your dna doesn't really change during your lifetime. (Unless when a dna mutation would happen but it's very rare)