Spermatozoa and eggs may or may not qualify as being alive. (I am uncertain about the scientific consensus) However they have a significant genetic difference from fetuses. The fetus is a different living being that either the sperm or the egg.
I doubt the 'problem' is of sufficient scientific significance to have an authoritative answer by consensus =9
I think that a gamete, when seen as an entirely independent entity, does not fit the definition of 'life'. However, it could be viewed as 'life-ness' when seen as a component of a larger system, as its existence is necessary for a sexual being to be considered alive.
It should also be noted that while a human (i.e. Homo Sapien) egg / sperm indeed lacks the material to grow into a fully formed Homo Sapien without artificial efforts, this lack is
quantitative, not
qualitative in nature.
In other words, a sperm can't become a fetus all by itself, not because it doesn't have all the necessary genes, but because it doesn't have
enough of it.
This implies that 2 eggs, with artificial help, CAN become a fetus without introducing additional genetic material.
Therefore, regarding this statement:
Neither ovas or ... those other things all on their own will become a living human. So you could destroy as much of them on their own as you want, but when you combine them, then you've got what could be a person one day.
If one were to make arguments based on necessity, that is untrue. Only ONE egg can be destroyed at maximum without destroying an amount of genetic information sufficient to construct a Homo Sapien.