Question

In the developing chick vertebral limb bud, the zone of polarizing activity (ZPA) organizes a pattern along the anteroposterior axis. Transplantation of the ZPA from a posterior to anterior position:___________

Answer 1

Answer:

Apical ectodermal ridge

Explanation:

Apical ectodermal ridge (AER) is a structure that forms from the ectodermal cells at the distal end of each limb bud and acts as a major signaling center to ensure proper development of a limb. After the limb bud induces AER formation, the AER and limb mesenchyme—including the zone of polarizing activity (ZPA)—continue to communicate with each other to direct further limb development.