Human beings come from reproductive cells, they don't come from non-reproductive cells such as tumors.
Tumour cells
are reproductive; that's what makes them so dangerous. If tumour cells don't reproduce themselves, then the tumour doesn't grow.
The end, in determining when the organism becomes a human being (being that is human), is to know the truth of what it is.
IOW, your point is your point? You just managed to use 24 words to say absolutely nothing.
Is my statement about scientists untrue?
Your statement that you're doing what scientists do is untrue.
What about "its humanity" necessarily implies rights?
Human gametes don't meet the requirement for a human being (being that is human) of 45-47 chromosomes.
What do the number of chromosomes matter? There are other ways to differentiate humans from other life:
- sentience
- sapience
- self-awareness
- language ability
- construction and use of advanced tools
- fire-building
- manufacture and use of clothing
Human beings are unique from other animals in all these ways as well. Why use only chromosomes as the basis for our determination of what is a "human being"?
Also, I disagree with your point about chromosomes and human gametes:
- a human sperm or egg cell is a "being" in some sense.
- a human sperm or egg cell is also uniquely "human": it isn't dolphin, monkey or meerkat... human sperm and eggs are
human sperm and eggs.
So... if you're going to redefine "human being" as "a being that is human", then sperm and eggs fit that bill just as easily as an embryo.
If you're going to actually put some thought into the question of "what is a person", you'll realize that there's no viable, supported way to justify the claim that personhood begins at conception.
An egg or sperm separately do not meet the requirement for a human being (being that is human) of 45-47 chromosomes.
The embryo meets the two requirements for a human being (being that is human):
1) 45-47 chromosomes and
2) all the essential characteristics for life, including development.
A human egg and sperm are definitely "beings", and they are definitely "human", so apparently your requirement of 45-47 chromosomes (where did that come from, BTW?) is incorrect.
Edit: and BTW - if you consider a sperm cell and an egg cell together, they do have 46 chromosomes, even before they join. The chromosomes just happen to be in two separate containers.