Answer:
The correct answer is ''pharyngeal slits (or clefts) of invertebrate chordates.''
Step-by-step explanation:
The neural crest is a temporary structure that develops as the neural tube closes. Its migratory capacity and subsequent distribution during development is a basic point in the general embryonic development and of most organs and structures in particular.These cells contribute to the formation of head cartilage and tooth dentin in fish embryos; and a large number of tissues and structures are formed from the migration of neural crest cells. Invertebrate chordates are animals of the Chordata phylum that have a notochord at some point in their development, but do not have a backbone. With a hollow nerve cord, neural tube. It appears by invagination of the dorsal surface; the tube is formed with a central cavity lined by ependyma; the anterior part of the neural tube gives rise to the brain. The neurenteric canal is a communication channel between the neural tube cavity and the intestine. The pharyngeal clefts (pharyngotremia), originally used for food; It is a filtering device that retains food particles that are included in mucus and transported to the intestine. In fish it already acquires respiratory function. In the ventral part, a groove is formed with cilia and bands of glands: endostyle or hypobranchial groove.