Answer:
- multiple times
Explanation:
Blastopore is a term used in embryology to refer to an extremity that acts as a means of communication in the embryonic phase, bringing the digestive cavity into contact with the external one. The blastopore forms in the embryonic gastrula period, at which stage cell differentiation begins. Later, another extremity may arise, also during embryonic formation.
Depending on the group to which the animal belongs, this orifice may primarily perform the mouth function - as is the case with protostomies - or initially act as anus of the organism - in the case of deuterostomies.
In either case, we can say that throughout evolution the final detecting of blastoporos has changed several times.
