<prompt> Monochorionic monoamniotic twins occur when splitting of zygote occurs:At bilaminar germ disc stageAt 8 cell stageAt 2 cell stageAt early blastocyst stage  <response>: Ans. is d, i.e. At early blastocyst stageMonochorionic: Monoamniotic twins are seen when division occurs at more than 8 days which means Blastocyst is formed we all know Implantation occurs in stage of blastocyst and implantation begins by 6 to 7 days after fertilization and is completed by 10th day after fertilization. Hence between this time the stage is Blastocyst. 