Planarians are flatworms, and they’re masters of regeneration with virtually unlimited capacity to regenerate any missing tissue or body part lost to injury or aging.
Structurally joints don’t bend both ways because there are physical components within their design that prevent or resist motion. This could be bone, such as the elbow joint, or it could be ligamentous restraint, such as in the knee.
To learn from a virtual body, it would need to be able to accurately simulate or predict how the body responds to internal and external changes.
In order for your brain to think, you need nerve cells that can detect information about the outside world and can transmit that information to other nerve cells.
We all have genes in our body, and our genes carry DNA. Siblings can inherit various genes from their parents and they don’t always get the same ones.