Question

The process of attachment of blastocyst in the endometrium of the uterus is known as
A. Placentation
B. Implantation
C. Gestation
D. Cleavage

Answer 1

After the egg is fertilized by a sperm the fertilized egg divides to form morula, which then again divides to blastocyst (also referred to as blastula). This blastocyst attaches to the endometrium (inner lining) of the uterus. This happens so that it can grow and develop into a baby (by getting oxygen and nutrients from the mother).

Complete solution:
After fertilization zygote is formed then this zygote divides to form a morula and then again it divides to form a blastocyst. This blastocyst adheres (attaches) to the uterine wall (endometrium) for receiving oxygen and nutrients from the mother. This attachment of blastocyst to the endometrium is called implantation.

So, the correct answer is option B.

Additional information:
In the placentation process, the formation of the placenta (the temporary organ which connects the fetus via the umbilical cord to the uterine wall) takes place. This happens so as to remove waste, exchange gases, provide nutrition, regulate temperature, and fight against infection).
Gestation is a time period in which the development of the fetus takes place. It is common in mammals (viviparous animals, which give birth to young ones). Its time interval is called the gestation period. For example, the gestation period of a human is about 9 months.
The initial cell divisions that occur after fertilization of an egg to develop into an embryo is called cleavage.

Note: Sometimes the blastocyst does not attach to the uterine wall but attaches to some other place than the uterine wall. This is called an ectopic pregnancy. This inhibits the development of a fetus.