Why two parent who a affected will not have any normal children but parent without hartnups disease could have child with hartnups

Photo means light and synthesis means combination so combination of light

1) the mayans built pyramids just like the egyptians. the mayans also used hieroglyphics like them.2) power was passed down by family. for example, if the father dies, the son would be the next king.3)they both built pyramids for their structures.4)the main crop for the mayans was maize.5)they also grew manioc, beans,  squash,  amaranth, and chile peppers.