Q.The average foetal heart beat rate is :

After implantation, the blastocyst's inner cell mass splits into an epiblast (ectoderm) and hypoblast (endoderm), with mesoderm forming between them in a process called gastrulation, producing the three primary germ layers from which every organ is built during organogenesis (ectoderm to nervous system, epidermis, mammary glands; mesoderm to connective tissue, bone, muscle, the urinogenital organs; endoderm to the gut/respiratory lining, liver, pancreas, thyroid). Four extra-embryonic membranes support the embryo: the fluid-filled amnion (cushioning, temperature regulation), the yolk sac (earliest blood cells), the allantois (structural base of the umbilical cord), and the chorion (outermost membrane, whose chorionic villi combine with uterine tissue to form the placenta). The placenta is a temporary endocrine organ that exchanges nutrients/gases/waste between mother and foetus and secretes …