Question

Which of the following statements in relation to cell movement during gastrulation in Sea urchin is/are correct?

• A. {Delamination leads to the formation of endoderm}
• B. {Ingression leads to the development of mesoderm}
• C. {Involution leads to the development of ectoderm}
• D. {Invagination leads to the development of endoderm}

Hint:

In Sea urchin gastrulation, ingression leads to mesoderm formation, while invagination is responsible for forming the endoderm.

Answer 1

The Correct Option is B, D

- Ingression (option B) is a process during gastrulation where cells move inward from the surface to form the mesoderm layer. The mesoderm gives rise to structures like muscles, bones, and the circulatory system.
- Invagination (option D) is the inward folding of the cell layer, which leads to the formation of the endoderm, the innermost germ layer. The endoderm will later form the digestive tract and other internal organs.
Other processes, such as delamination and involution, are important in some organisms but not directly involved in the processes mentioned for the Sea urchin gastrulation. Delamination leads to the formation of separate layers, and involution helps in ectoderm development, but it does not directly result in mesoderm or endoderm development in Sea urchins. Thus, the correct answer is (B) and (D).