Embryonic Folding — Third & Fourth Weeks

Embryonic Folding MCQs: practice questions

Sample Embryonic Folding multiple-choice questions from Third & Fourth Weeks.

1. What is the overall developmental purpose of folding?

   • A. To establish chromosome number
   • B. To produce gametes
   • C. To reorganize the embryonic disk into the basic three-dimensional body plan
   • D. To form trophoblast
   • E. To complete fertilization

2. What happens to part of the yolk sac during embryonic folding?

   • A. It becomes the neural crest
   • B. It becomes the placenta
   • C. It becomes the neural tube
   • D. It is incorporated into the embryo as the primitive gut tube
   • E. It becomes the kidneys

3. What does lateral folding primarily alter?

   • A. The chromosome number
   • B. Only the placenta
   • C. The transverse body shape and ventral body-wall closure
   • D. Only the neural crest
   • E. The genetic sex

4. What happens to the amnion during folding?

   • A. It becomes the yolk sac
   • B. It becomes the neural tube
   • C. It disappears
   • D. It expands around the embryo
   • E. It becomes the placenta

5. What does craniocaudal folding primarily alter?

   • A. Only the chromosome number
   • B. Only the neural crest
   • C. Only the placental villi
   • D. Only the germ-cell population
   • E. The cranial and caudal relationships of embryonic structures

6. In how many planes does embryonic folding occur?

7. What happens to the lateral edges of the embryo during lateral folding?

8. What structure is formed by incorporation of yolk-sac endoderm?

9. What happens to the cranial end of the yolk sac during folding?

10. Which process accompanies incorporation of yolk sac into the embryo?

11. Which process helps close the ventral body wall?

12. Which structure is not itself formed by embryonic folding?

13. What happens to the connecting stalk during folding?

14. What happens to the caudal end of the yolk sac during folding?

15. What promotes lateral folding?

16. What is the geometric result of embryonic folding?

17. What happens to the primitive gut during folding?

18. What are the two major types of embryonic folding?

19. What is the main embryonic source of the primitive gut tube?

20. What happens to the embryo's lateral body walls during folding?

21. What is the major consequence of folding for the embryo's body plan?

22. What embryonic structure remains connected to the yolk sac through the vitelline duct?

23. Which embryonic structure contributes specifically to lateral folding by its growth?

24. What promotes craniocaudal folding?

25. Which rapidly growing organ system contributes to craniocaudal folding?

26. What happens to the embryonic disk during folding?

27. What happens to the cardiogenic region during craniocaudal folding?

28. What does lateral folding bring together?

29. Which extraembryonic structure contributes to both types of folding?

30. What is the relationship of the gut tube to the yolk sac after folding?