When two oocytes are released and fertilised by two different sperms, forming two zygotes, which develop separately, the offsprings are called dizygotic twins.
Definitions [4]
Definition: Twins
When two embryos develop simultaneously in the same uterus and two offsprings are delivered at the same time, they are called twins.
Definition: Monozygotic Twins
When a single embryo divides into two groups of cells within 8 days after zygote formation, and both develop into separate embryos, they are called monozygotic twins.
Definition: Conjoined Twins (Siamese Twins)
If the embryo splits into two groups after 8 days of zygote formation, the resulting twins may be born with body parts joined together, and some organs may be common. Such twins are called conjoined twins.
Definition: Dizygotic Twins
