Bilaminar Germ Disc MCQ Quiz | Embryology

Welcome to the Embryology quiz on the Bilaminar Germ Disc, a crucial stage in early human development. This quiz is specifically designed for MBBS students to test and reinforce their understanding of the events occurring during the second week of gestation. You will explore the differentiation of the inner cell mass into the epiblast and hypoblast, the formation of the amniotic cavity and yolk sac, and the development of extraembryonic tissues. This formative assessment will help you master key concepts essential for your embryology curriculum. After completing the 25 questions, you can submit your answers to see your score and review the correct responses. You can also download a PDF of all questions with their correct answers for future revision.

1. The bilaminar germ disc is formed during which week of embryonic development?

2. The inner cell mass differentiates into two distinct layers. The layer of tall, columnar cells adjacent to the amniotic cavity is known as the:

3. The hypoblast consists of which type of cells?

4. The amniotic cavity forms as a small space within the:

5. The cells that line the roof of the amniotic cavity, derived from the epiblast, are called:

6. The exocoelomic membrane (Heuser’s membrane) is formed by cells migrating from the:

7. The primary yolk sac is also known as the:

8. The extraembryonic mesoderm is a new layer of connective tissue that appears between the inner surface of the cytotrophoblast and the outer surface of the exocoelomic cavity. Its origin is thought to be from the:

9. The extraembryonic coelom (chorionic cavity) forms by the coalescence of large cavities within the:

10. The extraembryonic somatopleuric mesoderm lines the:

11. The extraembryonic splanchnopleuric mesoderm covers the:

12. The secondary (definitive) yolk sac is formed when:

13. The connecting stalk, which later becomes the umbilical cord, is derived from the:

14. Which structure establishes the uteroplacental circulation during the second week?

15. The chorion is a composite structure formed by which three layers?

16. The prechordal plate, a localized thickening of the hypoblast, indicates the future site of the:

17. At the end of the second week, the bilaminar germ disc is composed of:

18. What is the fate of the primary yolk sac remnants after the formation of the secondary yolk sac?

19. The decidua reaction occurs in the endometrial stroma. This involves the accumulation of:

20. Which of the following structures is NOT part of the conceptus at the end of the second week?

21. The epiblast gives rise to the three primary germ layers (ectoderm, mesoderm, and endoderm) during which process?

22. By day 9, the blastocyst is completely embedded in the uterine endometrium. The defect in the epithelium is closed by a:

23. An ectopic pregnancy most commonly occurs when the blastocyst implants in the:

24. What is the primary role of the hypoblast?

25. The two cavities present at the end of the second week are the: