Web Results
Identical twins come from one ovum, which, after fertilization, divides in two and develops into two separate individuals. Fraternal, or dizygotic, twins occur when the mother produces two eggs in one monthly cycle and both eggs are fertilized.

Twin - Wikipedia

en.wikipedia.org/wiki/Twin

Monozygotic twins can develop differently, due to different genes being activated. More unusual are "semi-identical twins".

Identical twins - how do the happen, chances and risks of identical ...

www.huggies.com.au/childbirth/multiple-births/twins/identical

What causes identical twins or monozygotic twins? Find out the chances of having identical twins and the risks involved. Huggies.com.au.

www.ask.com/youtube?q=How Are Identical Twins Made?&v=sOBvRhXIJN4
Nov 6, 2013 ... Identical Twin Formation-First time ever witnessed The Cleavage of a ... IN THE WOMB DURING PREGNANCY - How TWINS are made?

Twins - identical and fraternal - Better Health Channel

www.betterhealth.vic.gov.au/health/conditionsandtreatments/twins-identical-and-fraternal

To form identical twins, one fertilised egg (ovum) splits and develops two babies ... The self-contained halves then develop into two babies, with exactly the same  ...

Twin pregnancy - identical and fraternal twins - single fertilized egg ...

www.baby2see.com/multiples/twins.html

With identical twins, one egg (zygote) from the mother is fertilized by one sperm ... they may develop separate placentas (chorion) and separate sacs (amnion).

USATODAY.com - How eggs split to form identical twins

usatoday30.usatoday.com/news/science/wonderquest/2001-05-09-why-twins-form.htm

May 9, 2001 ... How eggs split to form identical twins Q: In the case of identical twins, what triggers a single ... This is the stuff that an embryo will develop from.

How are non-identical twins made? | Reference.com

www.reference.com/science/non-identical-twins-made-a07b33173988e856

Nonidentical twins occur when a woman produces two separate eggs that are then fertilized by two different sperm cells. The resulting twins sometimes look ...

Twins, triplets, and other multiples | womenshealth.gov

www.womenshealth.gov/pregnancy/you-are-pregnant/twins-multiples.html

Identical twins look almost exactly alike and share the exact same genes. Most identical twins happen by chance.

Study: Identical Twins Caused by 'Embryo Collapse' | Fox News

www.foxnews.com/story/2007/07/05/study-identical-twins-caused-by-embryo-collapse.html

Jul 5, 2007 ... LYON, France – Scientists proposed a new theory this week for how identical twins are formed as embryos, in a discovery that may improve a ...