In assisted reproductive technology after in vitro fertilization, what is transplanted in fallopian tube?
Ovum from donor female and sperm from donor male are fertilized in laboratory(in vitro fertilization). The zygote or early embryo(upto 8 blastomeres stage) then transferred to fallopian tube called zygote intra fallopian transfer or ZIFT. So, the correct answer is 'Embryo upto 8 blastomeres, if zygote is not transplanted'.