but every woman has xx chromosomes and that binds us as a group, our basic biology.
Hmmm I'm not sure I agree with this.
There are a number of chromosomal abnormalities where a woman might not have XX and still be female.
I don't think it's our basic biology that binds is together, I think it's a mixture of the biology and the way that society treats us because of the perceived potential of that biology.
Being in the sex class that gestates the young means that we inevitably get treat differently to not being in that sex class.
I don't think this is necessarily a bad thing on its own, gestating young is a massive thing and accommodations need to be made socially and legally. When it becomes shit is when a value judgement is put on it and when women are expected to act and be a certain way personally and are punished when we don't conform.
Sex differences and and gender aren't the same thing, and I think it's totally reasonable to say 'women are the sex category that gestate the young so we need to make sure they have protections in law to make sure they are safe during that vulnerable time' or 'due to the fact that women as a class are smaller we need sex segregated spaces when they are vulnerable'
What's not reasonable to say is 'women gestate the young so all of them must be kind and caring and put everyone else before themselves'.
I don't think sexism comes from chromosomes alone, it's that layered with societal expectations of that biology.
A female fetus isn't aborted in India due to the chromosomes alone but because of what that society has decided about the value of those chromosomes.
Trans women don't experience this because everyone knows that trans women are in fact male and don't have the biological potential to gestate young.
Ok there might be the very very rare case where a trans woman is able to completely pass and no one knows she's trans but that's is not the case for the vast majority of them and would be the anomaly that proved the rule.
For instance a married trans woman in her 30's won't be passed over for a promotion in case she gets pregnant. (This is an example from my life, I can't have kids and it didn't stop it happening because they didn't know that, it was my perceived potential that was the issue).
I think when we untangle it and say it's just chromosomes that make us a woman then we do run the risk of ignoring people with intersex conditions and losing sight of the what those chromosomes signify.
I have no idea what chromosomes I have (I'm pretty sure I have XX but I've never been pregnant and I haven't had any tests so there's a slim chance I don't) but I have been socialised as female and the world perceives me as part of the sex class that gestates young with everything that goes with it.
I don't think you can untie the material biology of femaleness with being brought up female.
The TRA's say it's only the gender that matters and ignores the biology but I don't believe it's just the biology in itself either. It's all part of the female experience and quite frankly it's bloody ridiculous that the TRAs have put us in a position where we have to defend this.
We ALL know what a woman is. It's an adult human female.
A trans woman is not a woman because 1) they are not female
2) they have not been socialised as a female.
If a trans woman was able to be socialised as female they still wouldn't be a woman because they are male.
If we were able to change every cell in their bodies to female they still wouldn't be a woman because they weren't socialised as female.
This things are linked. I don't think we should concede female socialisation to the TRA's, we need it for lots of other fights.
(Sorry that was really long and I'm aware it wasn't all relevant to your original post, I just went off on a tangent).