Trans does not mean not. It's also not being used as a prefix, but short for transgender, which is an adjective (although it is a prefix within that adjective).

https://www.oed.com/viewdictionaryentry/Entry/247649;jsessionid=5EE84F821DF046846F76120C822898E7

This argument makes as much sense as saying a transnational corporation is not a corporation or that an interstate railroad is not a railroad.

I don't feel qualified to speak on the biological aspect of this, but I actually do have a degree in English and am confident in saying this linguistic argument is incredibly dumb.

Is there a reason why the word 'biological' has quotation marks around it?

Indeed there is. The reason is because biology is a lot more complex than a lot of people make it out to be and simplifying it into a binary is overly and misleadingly reductive. Thanks for asking.

Cis means near side and trans means across. They're latin prefixes, for example: Transalpine Gaul and Cisalpine Gaul refers to designated regions.

So, anyway, in gender terms
Trans means someone who has crossed to another gender, so a trans woman would be someone who wasn't a woman before.
Cis means someone who hasn't, so a Cis woman is someone who has always been a woman.

Although, I don't know any transgender people, or really anyone who has an opinion on it. So I am not actually sure if I have the accurate definitions here.

Personally, I'm inclined toward agreeing with this take on the matter because I'm the resident "terf" here. I don't get the phenom of gender identity, which is because I don't buy into the notion that "gender" is a real thing. In other words, I don't know what it even means to "feel female". That whole notion to me seems like a load of bullshit and the more I read about it, the more convinced I become that it is bullshit.

I freely admit to not knowing any trans-identified people offline personally and that that could very well be a factor in my persuasion. I'll also concede to being influenced by a woman I know who de-transitioned because she found gender identity to be bullshit too. And furthermore, I won't kid anyone here: personally, I find it kind of insulting that society takes such issue with cultural appropriation when it comes to everything from as serious as blackface down to matters as unserious as hairstyles and twerking, but somehow manages to find the idea of men going around claiming to actually be women and making an entire lifestyle of that totally unobjectionable and in fact offensive to criticize. Maybe I just lack the right kind of sensitivity and the fullest information that's available, but just being straightforward here about the impact of this stuff viscerally on me.

But look, all this said, I've got nothing against trans people as people. I don't dislike such persons and in fact have trans-identified friends online. (And yes, they're aware of my opinions.) I'm inclined to live and let live. But there is a movement of people out here who clearly don't feel the same way and that's where we really start running into problems.

J.K. Rowling is trying to craft out a nuanced position here that recognizes gender identity, but in a way that also acknowledges the socio-political significance of biological sex. I'm not sure that's a tenable position. I don't think the transgender movement will permit her any nuance on this subject. You either have to go along with their entire program of sex-neutralizing everything, all spaces, institutions, language, everything, or you're a bigot in their eyes. Women cannot have privacy rights or be in any way sheltered from "male-bodied persons", be it in contact sports, shelters for battered women, or even in prisons as far as the transgender movement is concerned. Women's privacy and safety has to be completely sacrificed on all levels on the alter of politeness. Neither, for that matter, can anyone de-transition, or necessarily even just be lesbian (as in not sexually attracted to penises) for that matter to be in the clear with this movement. THAT belligerent attitude is why us "terfs" exist.

Were there any room, any socially acceptable space, for the J.K. Rowlings of the world to have their nuanced views, their concerns for the sex-based rights of women in addition to the safety and well-being of trans people...if women were allowed to embrace complex views like those of J.K. Rowling without being labeled "terfs" or transphobes or what have you...I don't think many feminists would continue to care about people's pronoun preferences. But that's not the world we live in, is it?

Seems simple to me.

Penis = man. Vagina = woman.

I agree with everything JK Rowling has said about transgenderism. once people saying that it's transphobic for a straight man or a lesbian woman to not want to be with a trans-woman they lost all sympathy from me

https://www.youtube.com/watch?v=dnJTF_jtPnU

Basically JK Rowlings TERF manifesto.

I don't have the energy to make a long post on my views on this subject but I do want to reject this notion that it purely psychological. 

When we talk about what consider feminine behavior vs masculine behavior the primary cause is not a difference between male and female brains but how human brains react to testosterone vs estrogen.  If you give a man estrogen they will start to show what people consider in society more feminine behavior.  They also plays a big role in brain development studies have found.

I say this because studies have shown that people who identify as Transgender MtF generally have a longer receptor gene for the sex hormone of testosterone which reduces it effectiveness at binding testosterone.  The research suggests that the decrees in testosterone levels in brain during development causes a more "feminized brain" which leads to identity as female vs male.

My point is that there are physicals developments of the brains that have been shown in multiple studies as the reason and it complete BS saying it about self-respect or any other way to you try to trivialize the matter by saying all they need is counseling.  I don't blame transsexual individuals in the slightest for finding it offensive suggesting that all they need is counseling just like any Gay/Lesbian would find it offensive to suggest they need counseling.

Is genitalia the extent of biology? Like I said, boiling biology down to genitalia is overly reductive, as it ignores things such as genetic variations and hormone levels, which also fall under the banner of the biology of sex.