Reference no: EM132680799

Question 1. How do dorsal determinants relocate from the vegetal pole of a Xenopus embryo to the future dorsal side?

Question 2. What molecular events lead to organizer formation in Xenopus (start with fertilization and conclude with the activation of siamois expression)?

Question 3. Describe the changes that occur in a Xenopus embryo at the midblastula transition (MBT).

Question 4. How did researchers determine the manner in which MBT is timed (include a description of tested variables)? What did they conclude?

Question 5. Does any transcription occur prior to the MBT? What are the pieces of evidence that suggest and or prove that there is or is not preMBT transcription?

Question 6. Describe gastrulation in general terms (not molecules involved) and the role it plays in the formation of the three germ layers; include a discussion of the blastocoel.

Question 7. What type of process does the ectoderm undergo during gastrulation? Describe this process.

Question 8. What type of movements do nonectodermal cells exhibit during gastrulation? effects of cell movements (all at the cellular level).

Question 9. Describe how TGF and Wnt signaling induce mesoderm.

Question 10. What role does fibronectin play in gastrulation?

Question 11. Describe neural induction of ectoderm at a molecular level; include cell types involved.

Question 12. What is the relationship between axis specification events that occur prior to the first cell division and the dorsal lip?

Question 13. Explain the role of the Wnt and BMP pathways, and their interrelationship, in intestinal (a) development (only Wnt), (b) maintenance (EXCLUDE discussion of the differentiated cell types themselves), and (c) cancer.

Question 14. Describe intestinal self-renewal. Include a discussion of the crypt/villus axis and stem cells.

Question 15. When do teratogens present the greatest risk to a developing embryo? Why?

Question 16. What is diethylstilbestrol, and how does it act as a teratogen (at a molecular level)?