Final answer:
The protective environment inside the mother's uterus is called the amniotic sac, which is a membrane filled with fluid that surrounds and protects the developing fetus.
Step-by-step explanation:
The Protective Environment Inside the Mother's Uterus
The protective environment inside the mother's uterus is known as the amniotic sac. This sac is an enclosed membrane that surrounds and protects the fetus during development. The amniotic sac contains amniotic fluid, which consists of water and dissolved substances. This fluid allows the fetus to move freely and also acts as a cushion to protect the fetus from injury. In contrast, the placenta is a spongy mass of blood vessels responsible for the transfer of nutrients and gases between the mother's blood and the fetus's blood. The uterine lining, or endometrium, is the lining where implantation of the embryo occurs, and the umbilical cord connects the fetus to the placenta, facilitating the exchange of nutrients and wastes.
With respect to the options provided in the question:
A) Placenta - helps form the fetal portion of the placenta
B) Amniotic sac - is a sac that contains fluid that surrounds and protects the fetus
C) Uterine lining - is the lining of the uterus where implantation occurs
D) Umbilical cord - provides a connection between the mother's and fetus's blood for the transfer of nutrients and gases
Therefore, the correct answer to the question 'The protective environment inside the mother's uterus is called the' is option B) Amniotic sac.