Question

Identical twins are also known as
A) Monozygotic twins
B) Dizygotic twins
C) Fraternal twins
D) Both B and c

Answer 1

Hint: Twins are the two offsprings produced from the same pregnancy. Zygosity is the degree of identity in the genome of twins.

Complete Answer:
- Fertilisation is the process of union of sperm and ova to form a zygote. After fertilisation, the zygote forms an embryo in the uterus where it implants itself to the fetus.
- A fetus develops along in the womb but sometimes multiple zygotes are formed as a result of which multiple offsprings are produced.
- The Twins can be monozygotic, meaning they develop from one zygote which splits and forms two embryos. They are also known as identical twins as all the phenotypic features are similar.
- But if each twin develops from a separate egg and each of the egg is fertilised by different sperm. This leads to dizygotic twins. They are also called fraternal twins. They are un-identical. They are just like siblings who have taken birth at the same time. They are a common type of twins.

Thus the correct answer is (A). Identical twins are called monozygotic twins.

Additional Information: The dizygotic twins have different placenta whereas the monozygotic twins share the same placenta. Monozygotic twins occur rare like 3 in 1000. IVF creates dizygotic twins.

Note: Monozygotic twins are genetically very identical and have the same sex. Identical twins however do not have the same fingerprints.