Imagine looking at a slide of a cross section of a frog embryo that has just completed neurulation.Which is the sequence of structures you should see, beginning with inside the gut of the embryo and moving outward?
A) Gut endoderm, epidermis, notochord, neural tube
B) Gut ectoderm, notochord, neural tube, epidermis
C) Gut endoderm, neural tube, epidermis, notochord
D) Gut ectoderm, epidermis, neural tube, notochord
E) Gut endoderm, notochord, neural tube, epidermis

Question

Quizplus · Accepted Answer

The correct sequence from the inside of the gut outward in a frog embryo after neurulation is gut endoderm, notochord, neural tube, and then epidermis. The gut is lined by endoderm, the notochord is a mesodermal structure that provides signals for the formation of the neural tube, the neural tube itself is derived from ectoderm and will develop into the central nervous system, and the outermost layer is the epidermis, also derived from ectoderm.

Imagine Looking at a Slide of a Cross Section of a Frog