Unit 1

Question 1

What is the animal and vegatal pole?

Answer 1

Animal pole: top of Xenopus embryo; where sperm enters
Vegetal pole: bottom of Xenopus embryo;

The point opposite the sperm entry becomes the dorsal lip of the blastopore

Question 2

Other names for dorsal lip of the blastopore

Answer 2

Nieukwoop Center, Spemann-Mangold, Henson Node (chicks)

Question 3

How is the Nieukwoop Center formed?

Answer 3

The NC is formed opposite sperm entry; location is determined by dorsalizing factors after the cortical rotation.

These factors activate Wnt which leads to the dorsal lip of the blastopore

Question 4

What is Spemann’s Organizer?

Answer 4

the region that indicates initiation of gastrulation

Question 5

Noggin, chordin, and follistatin are all ___ inhibitors

Answer 5

BMP inhibitors

Question 6

How was it proven that neural tissue was the default in the ectoderm?

Answer 6

The animal cap of the Xenopus embryo was isolated.

When kept whole&raquo_space; epidermis
When dissociated&raquo_space; neural

Neural is default when there is no cell-cell communication.