Implantation occurs at the stage of
C i.e. Blastocyst- Barrier is provided by fusion / feilin (not Ach)Q. Fusion reduce the membrane potential of ovum that prevents polyspermy by not allowing the others sperms to enter.- Morula is a 16 cell stage, surrounded by zona pellucida. Barrier is provided by fusiotVfetilin.QImplantation occurs at the stage of blasto cystQ.
Zygote
Morula
Blastocyst
Primary villi