Gender absolutely exists. We couldn't have babies without a male/female genitals. Our chromosomes support that. Honestly, not too sure if I buy into people's perceived genders but it's not my battle to fight. I will say, though, that I take issue with the LGBT movement labeling straight, regular folk like myself. No, I am not "cis-gendered" as I don't "label" myself that way. I'm female, that's it. You can think, feel, and call yourselves anything you want though. That's YOUR label. I don't have to agree with it. er.
Im not sure if it's just me but I actually find this a little offensive. So far this has been a friendly debate with nothing needed about how you label yourself however, I'm not sure cis-gendered could be considered a label, more of a description of someone whose sex matches their gender. It's funny though how you are happy to label yourself as one of those straight, regular folk. A few corrections for you though, it is entirely possibly to conceive without male/female genitalia and many babies are born each year through IVF with ICSI. What is needed are male and female sex cells, sperm and eggs. There are also disorders where people's chromosomes do not match their genitalia, assigning sex is not always as simple as you assume.