How are identical and non-identical twins produced?

Answer 1

When an egg is fertilized by a sperm, it becomes a zygote. That zygote goes through cell division to become an embryo.

Sometimes, the zygote splits and becomes two separate organisms - they will be identical twins. If the zygote splits and separates multiple times, you can get triplets or even quadruplets. They will all be (more-or-less) genetically identical.

If two eggs are released during ovulation and each one is fertilized (by a separate sperm) then you will have fraternal (non-identical) twins. Again, if multiple eggs are released (for example, when a woman is undergoing fertility treatments) and each one is fertilized by a separate sperm, you can get triplets, quadruplets, etc. They will all be genetically different and can even be different sexes.

Answer 2

Identical twins occur when the fertilized egg, instead of splitting into two connected cells, splits into two separate cells. Non-identical or fraternal twins occur when the mother releases two eggs which are fertilised by two sperm and both implant.

Answer 3

Identical twins are produced when a single fertilized egg spontaneously splits into two embryos, resulting in two individuals with the same genetic material. Non-identical twins, also known as fraternal twins, occur when two separate eggs are fertilized by two different sperm, leading to individuals that are no more genetically similar than siblings born at different times.

Answer 4

Identical twins occur when the fertilized egg, instead of splitting into two connected cells, splits into two separate cells.

Answer 5

Fraternal twins are made when two eggs are fertilized by two differents sperm so they are like brother and sister just born together

Answer 6

non identical twins are made when occasionally during the woman's period she lets two eggs out at the same time, which are fertilised by two sperms to form non identical twins.