The attachment of the mammalian blastocyst to the uterine wall is known as:

What is formed by the fusion of male and female gametes?

The $Zona$ $pellucida$ of a mammalian egg serves which of the following purposes?

Cleavage divisions differ from normal mitotic divisions in that

$A$: Every cell of the body contains the same genetic material as the zygote. $R$: The zygote is formed by the fusion of male and female gametes.

Select the correct statement.