Answers

2016-06-24T21:49:31+08:00
It is like a bag inside a woman's reproductive system and holds the fetus for 9 months
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2016-06-24T22:07:03+08:00
The wall of the uterus will thicken as a response to hormonal changes that regulates the menstrual cycle. it is this thickening that allows the embryonic sac to be attached by means of blood vessels and umbilicus  that also supplies the fetus with the needed nutrients for growth and development
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