You mean, if science can clone a human, would it be a human from the moment it became a zygote? Yes, of course.
You realize it will never be a zygote? A zygote is only formed from the union of sperm and egg.
Unless you want to call a skin cell fused with an enucleated egg cell a "zygote".
No, it may not turn develop into a human unless you physically turn it into one.
Actually I don't know what would happen if you put it in the correct environment. There is no "physically turning it into one" line I'm aware of.
Sure, and there can be reasonable criteria for when a human should die with that logic.
Or when a human body is not a person anymore. Why not use the same criteria to determine when a group of cells attains "person hood"?
But the question is not what reasonable criteria can we come up with to decide what humans can live. The question is, why are you deciding, after a human is alive, whether they are allowed to live or not?
Because it's nearly impossible to protect zygotes without incredible invasions into a woman's privacy and reproductive decisions. And you can't convince me, nor most of the rest of humanity that a one celled zygote deserves the same rights as a human being anyway. Asserting it over and over doesn't make it true.
A zygote inside of a woman's body cannot be seen or detected by any means I'm aware of. In fact any attempts to do so might result in the failure to implant (death) of the zygote.
The only way you can "protect" zygotes is to ban all forms of hormonal birth control leaving you with condoms and surgical means. If you do that, you'll have a massive black market in the substances. What do you plan to do? Throw women in jail for using birth control pills? Screen them for having IUDs? Follow women to see if they miss their normal cycles, then prosecute them if they fail to give birth?
It quickly becomes ludicrous, especially since you're often the same people that decries invasive government. You don't get much more invasive than a vaginal probe.