Pregnancy begins with implantation of
Embryo
Fertilised ovum
Blastopore
Blastocyst
Formation of segmentation cavity shows
Identify figure
Fertilization occurs in human, rabbit and other placental mammals in
$A$ : In morula stage the cells divide without any increase in size.
$R$ : Zona pellucida remains intact till cleavage is completed.
The cleavage is such method of divisions of fertilized egg in which the egg