My answer is that a gamete is not a human being, it is a part of a human being. Since a part is a different thing than a whole a gamete does not possess the same intrinsic rights or dignity that the human being possesses. They are different essences. As I tried to explain earlier, a gamete is an incidental property of the essence of humanness. Ten fingers are an incidental property of humanness. That some particular instances of human beings do not have ten fingers says nothing about their humanness. It is a different category, and it is a mistake to confuse them.
Cordially,