'While developing within the mother'. You've probably noticed that children tend to look like a combination of the characteristics of their parents, right? This is because the child receives a mixture of the parent's genes.

With no clouds, they are very easy to see on Dune, as well as the moons, Muad'dib and Qhamsa. Shai-hulud, the great sandworm is also quite breathtaking when he emerges.