The zygote passes through several developmental stages until implantation. Describe each stage briefly with suitable diagrams.

(N/A) The developmental stages from zygote to implantation are as follows:
$1$. Zygote Formation: Fertilization of the ovum by a sperm in the fallopian tube results in the formation of a diploid zygote.
$2$. Cleavage: The zygote undergoes mitotic divisions called cleavage as it moves through the isthmus of the oviduct towards the uterus.
$3$. Morula Stage: These divisions produce $2, 4, 8,$ and $16$ daughter cells called blastomeres. The embryo with $8-16$ blastomeres is called a morula.
$4$. Blastocyst Stage: The morula continues to divide and transforms into a blastocyst. It consists of an outer layer called the trophoblast and an inner cell mass. The blastocyst moves into the uterus.
$5$. Implantation: The blastocyst embeds itself in the endometrium of the uterus,a process known as implantation,which leads to pregnancy.