Question

Which of these events occurs first? select one:
a. cleavage
b. implantation
c. formation of the placenta
d. gastrulation?

Answer 1

The event that occurs first is cleavage. This occurs when the zygote (cell that is fertilized) divides itself and creates morula, which is a grouping of cells. Essentially, cleavage is the fertilization and division of the cell.