Question

differentiate between monozygotic and dizygotic twins

Answer 1

Hy,
Monozygotic twins are those which are formed from a single zygote. The zygote under certain conditions, divide or breaks into two zygotes.
These twins are morphologically similar, but not genetically. Mind you that, DNA of even the Monozygotic twins is different from each other, irrespective of the fact that they developed from a single zygote.
Dizygotic twins are formed, when ovary produces two eggs and those two eggs are fertilised by two different male Sperms. So, two individuals develop from two different ova. Two zygotes develop. These two individuals are morphologically and genetically different.
In Dizygotic twins, probability of one child being male and other being female is high.

References- Textbook of Human Embryology by Dr. Inderbeer Singh, Textbook of Physiology by Dr. A. K. Jain, Zoology by Akash Institute, Biology book for Class 12th

Hope it helps
Regards
Dr Chinmay
Thanks

Answer 2

Because fraternal, or dizygotic, twinsare 2 separate fertilized eggs, they usually develop 2 separate amniotic sacs, placentas, and supporting structures. Identical, or monozygotic,twins may or may not share the same amniotic sac, depending on how early the single fertilized egg divides into 2.