I expect that there are some things that are "universal" and some that aren't.
For example, if life--any life--forms on a planet, it is likely that some macro-organisms will evolve that consume other organisms.
On Earth we have plants that are eaten by animals that are eaten by other animals and so forth and these all act as a form of "battery" in that solar power is converted into energy and increasingly stored in larger "blobs". This is almost necessary for large life to exist. Well, for carnivores at least (eg many whales eat krill and there are a bunch of filter-feeders).
So the chemistry of life elsewhere may be similar or it may be totally different but something like a carnivorous trait is I think almost inevitable.
Once you have that then certain other traits became almost inevitable. Flight, for example. It may be that flight is impossible given local conditions (eg high gravity, atmosphere or the lack thereof). That doesn't mean we'll end up with feathers and birds per se but evolutionary pressure will likely mean available niches are filled. On Earth almost every environment has life, only really excluding the coldest, driest, highest and deepest of places.
Also, consider sensory organs. I expect the ability to detect parts of the EM spectrum, sound, taste/smell and tactile feedback will all likely evolve with sufficient time. And that itself has consequences for what life looks like.
For example, if life--any life--forms on a planet, it is likely that some macro-organisms will evolve that consume other organisms.
On Earth we have plants that are eaten by animals that are eaten by other animals and so forth and these all act as a form of "battery" in that solar power is converted into energy and increasingly stored in larger "blobs". This is almost necessary for large life to exist. Well, for carnivores at least (eg many whales eat krill and there are a bunch of filter-feeders).
So the chemistry of life elsewhere may be similar or it may be totally different but something like a carnivorous trait is I think almost inevitable.
Once you have that then certain other traits became almost inevitable. Flight, for example. It may be that flight is impossible given local conditions (eg high gravity, atmosphere or the lack thereof). That doesn't mean we'll end up with feathers and birds per se but evolutionary pressure will likely mean available niches are filled. On Earth almost every environment has life, only really excluding the coldest, driest, highest and deepest of places.
Also, consider sensory organs. I expect the ability to detect parts of the EM spectrum, sound, taste/smell and tactile feedback will all likely evolve with sufficient time. And that itself has consequences for what life looks like.