Question

1.Describe a developmental characteristic that Echinodermata and humans share.

2.In the fetal pig, the endocrine gland that occurs between the lobes of the thymus, on the ventral side of the trachea, a few centimeters caudal (posterior) to the larynx is called what?

3.After birth, in the pig, blood that is carried from the small intestines enters the liver via the "X" vein, and from the liver blood is carried all the way to the heart's atrium ­­­­via the vessel called "Z".

What is "X"?

What is "Z"?  

Answer 1

Answer-

1) Animal development include 2 phenomena based on what structure appear first during fetal development

Animals could be Protostome and Dueterostome

Protostome means blastopore opens with mouth- present in invertebrate except Echinoderms

Deuterostomes mean blastopore opens with @nus (Defecation pore) or first opening is @nus- present in all vertebrates and Echinoderms.

In this way echinoderms share ancestry with human beings.

2) The endocrine gland is Thyroid gland .

3) X is hepatic portal vein and Z is hepatic veins