Question

What is zygote?

Answer 1

Hint:- Fertilization is a process in which two distinct gametes are fused together and form a new single-cell called a zygote (diploid). These gametes are the male gamete and the female gamete, male gamete is small and motile and called sperm while the female gamete is large in size and immotile and called an egg cell or ovum. This process of fertilization takes place inside the female body, the outsider's sperm cell comes inside the female body and fuses the egg cell so it is also known as fertilization of Egg

Complete step-by-step solution:-
Fertilization is always initiated with attachment of sperm with zona pellucida (found around an egg), then acrosome of sperm release an enzyme which digest the zons pellucid, and then the head of sperm penetrates into the plasma membrane of egg or oocyte and sperm nucleus passes into the cytoplasm. Within the oocyte, the haploid set of sperm and egg chromosome are initially separated from each other and constitute respectively the male and female pronuclei. They subsequently fuse to form a diploid nucleus; this fertilized egg is known as the zygote. Zygote represents itself as a single cell with diploid set of chromosomes. Further zygote is divided for development into smaller cells called blastomeres (a group of cells is called blastocysts). After a few five days of fertilization, blastocysts move toward the uterus from the fallopian tube, and attached tightly to the uterine epithelium such phenomenon is called implantation.

Note:-
A zygote is further developed into embryo and after organogenesis in embryo, it becomes a fetus. Day 1 to two month’s baby in the uterus is known as embryo and two months to nine months baby is known as fetus.