Untrue about ectodermal cleft is

D. i.e. None of the above1st pharyngeal arch form maxillary prominence (producing maxilla & zygomatic bones by intramembranous ossification)Q and mandibular prominence (producing malleus & incus by endochondral ossification)Q. Mandibular division of trigeminal nerve is the nerve of 1st arch- Muscle of facial expression (including buccinator) develop from 2nd arch & so are supplied by facial nerveQ (not mandibular nerve). Stapes is the skeletal element of 2ttd arch.Thymus develops from 3"1 endodermal pouchQ. Ultiinobranchial body forming parafollicular cells of thyroid are derived from 5deg' branchial (endodermal) pouchQ