Fertilisation and Implantation Questions in English

(C) The process of cleavage in the zygote leads to the formation of a $16$-celled stage called the $Morula$. The $Morula$ continues to divide and transforms into the $Blastocyst$. It is the $Blastocyst$ that gets embedded or implanted into the endometrium of the uterus to initiate pregnancy.

(D) The term $Test$ $Tube$ $Baby$ refers to the process of $In$ $Vitro$ $Fertilization$ $(IVF)$,where fertilization occurs outside the body in a laboratory setting.
After fertilization,the resulting zygote or early embryo (up to $8$ blastomeres) is transferred into the fallopian tube,a procedure known as $Zygote$ $Intra$ $Fallopian$ $Transfer$ $(ZIFT)$.
$GIFT$ ($Gamete$ $Intra$ $Fallopian$ $Transfer$) involves transferring gametes,not embryos,and is used when fertilization cannot occur in vivo.
$IUI$ ($Intra$ $Uterine$ $Insemination$) is a technique where sperm is placed directly into the uterus.
$ICSI$ ($Intra$ $Cytoplasmic$ $Sperm$ $Injection$) is a specialized procedure to form an embryo in the laboratory.
Therefore,$ZIFT$ is the specific method used to transfer the embryo formed via $IVF$ into the fallopian tube.

(B) The correct answer is $B$.
Implantation is the process by which the blastocyst attaches to the endometrium of the uterus.
This process is primarily influenced and maintained by the hormone $Progesterone$,which is secreted by the corpus luteum.
$Progesterone$ prepares the endometrium for implantation and maintains pregnancy by preventing the contraction of uterine muscles.