[ That gives Gamora pause, because she's never actually thought about it before. They're all their own species and as she'd never had anything to consider home - traveling around the universe with Thanos - she's not conditioned to think of one as normal and the rest different. ]

The three major races of the universe - the Skrulls, the Kree, and the Shi'ar are all bipedal with noticeable physical differences between the sexes. After that, it blurs together, but at a guess - most are similar enough.