Question

The stage in which implantation of the fertilised egg occurs in the uterine wall
is called (morula, blastocyst, embryo, gastrula)​

Answer 1

Explanation:

In humans, blastocyst formation begins about 5 days after fertilization when a fluid-filled cavity opens up in the morula, a ball of cells. The blastocyst has a diameter of about 0.1–0.2 mm and comprises 200–300 cells following rapid cleavage (cell division).