Question

Spreading of presumptive ectoderm on underlying mass of cells is?

• A. Epiboly
• B. Invagination
• C. Ingression
• D. Delamination

Answer 1

The correct option is A Epiboly

A. During epiboly, a sheet of cells spreads by thinning i.e the sheet thins, while its overall surface area increases in the other two directions.

B. During invagination, an epithelial sheet bends inward to form an inpocketing.

C. During ingression, cells leave an epithelial sheet by transforming from well behaved epithelial cells into freely migrating mesenchyme cells.

D. The definition of a delamination is a separation into layers or initial splitting of the cells in an embryo.

So, the correct answer is 'Epiboly'.