Table of Contents
- 1 Is it possible for a boy girl pair of twins to be genetically identical Why or why not?
- 2 Can identical twins be the opposite gender?
- 3 How twins are formed in humans?
- 4 What is a polar opposite twin?
- 5 Can a set of boy and girl twins be identical?
- 6 What are the possible sex combinations of fraternal twins?
Is it possible for a boy girl pair of twins to be genetically identical Why or why not?
In 99.9\% of cases boy/girl twins are non-identical. However, in some extremely rare cases resulting from a genetic mutation, identical twins from an egg and sperm which began as male (XY) can develop into a male / female pair.
Is it possible to have boy and girl conjoined twins?
Well, good question… technically not possible. Conjoined twins are identical twins, coming from the same fertilised egg so they will always be the same sex because their sex was determined at the point of fertilisation from the male sperm.
Can identical twins be the opposite gender?
Because identical twins share all of their genes, they can’t be of opposite sexes like fraternal twins can. But in the semi-identical twins, one set of chromosomes came from the egg, and the second set was made up of chromosomes from two separate sperm, Gabbett told Live Science.
What are Didi twins?
In a di/di pregnancy (more scientifically referred to as a dichorionic diamniotic pregnancy) the twins each have their own chorionic and amniotic sacs. Essentially, each of the babies is growing like they would as a singleton, but just a little more cramped, because they’re sharing the same womb.
How twins are formed in humans?
To form identical or monozygotic twins, one fertilised egg (ovum) splits and develops into two babies with exactly the same genetic information. To form fraternal or dizygotic twins, two eggs (ova) are fertilised by two sperm and produce two genetically unique children.
What are the 4 types of twins?
How Many Types of Twins Are There?
- Third type.
- Unique identical twins.
- Unique fraternal twins.
What is a polar opposite twin?
A Sub-Trope of the Odd Couple wherein the odd couple are twins, usually identical brothers or sisters (or cousins, as long as they’re still using the “identical appearance, contrasting personalities” motif). Extreme opposite is Single-Minded Twins or Creepy Twins.
What is a opposite twin?
When twins have opposite features from their sibling, they may refer to themselves as mirror twins. Some examples of mirrored features include: birthmarks. freckles.
Can a set of boy and girl twins be identical?
A set of boy/girl twins: Can only be fraternal (dizygotic), as boy/girl twins cannot be identical (monozygotic) Two boy twins: Can be either identical or fraternal (monozygotic or dizygotic) Two girl twins: Can be either identical or fraternal (monozygotic or dizygotic)
What causes identical twins to be made?
In rare instances, however, identical twins form from an egg and sperm that begin as males (sharing XY chromosomes) then change to become a male and female pair. This occurs when one half of the split fertilized egg loses a copy of its genetically encoded Y chromosome.
What are the possible sex combinations of fraternal twins?
Fraternal twins can be either two girls, two boys, or one of each. These are the possible sex combinations: Two girl twins can be either identical or fraternal (monozygotic or dizygotic). Two boy twins can be either identical or fraternal (monozygotic or dizygotic). A set of boy/girl twins can only be fraternal (dizygotic).
Are there genetically similar twins that are genetically different?
Twins That Are Genetically Dissimilar. While identical twins come from the same fertilized egg and share the same DNA combination, there are more possibilities for fraternal twins. Besides being the offspring of two sperm and egg combinations, they may have different genetic donors.