It has been proven by science many times over that we inherit our chromosomes at birth. Our eye color and skin type and all sorts of other things are in our genes. However, you could make a debate about whether or not nature versus nurture can influence these things in one way or another.
I think that humans inherit all of their chromosomes, and they do not mutate after we are born, because that is what the scientific evidence shows. Chromosomes can be manipulated after birth, but they can never actually be truly changed into something. Chromosomes are something that must be given upon birth.
I think that humans inherit all of their chromosomes. I think that chromosomes are inherited from our parents and make up the way we look and see the world. I do not think that as we continue to grow that we have the ability to make more or less chromosomes.
It has been shown that humans inherit all of their genetic materials from their parents when they are conceived. Although in some cases of gene therapy, doctors can change a person's DNA, this is not a natural process. When left alone, a person cannot change their genetic material at all.
I believe it is possible to feel both items are possible in this question. I do believe all chromosomes are inherited, if the balance is off there is a problem and it's generally very evident. At the same time chromosomes can also mutate, which is fairly common within humans and is part of the way we evolved.