Final answer:
The hard palate completes fusion in utero during embryonic development, typically between the 9th and 12th weeks of pregnancy.
Step-by-step explanation:
The hard palate completes fusion in utero during embryonic development. It is formed by the midline fusion of the horizontal plates from the right and left palatine bones and the palatine processes of the maxilla bones. This fusion typically occurs between the 9th and 12th weeks of pregnancy. Cleft palate, a birth defect where the two halves of the hard palate do not properly fuse, can occur if there is an error in this developmental process.