Identical Twins

anonymous asked:

Who are teagan and Sara and why do you delete them? Are they sisters or something

they’re a band!! and they’re also sisters — identical twins, and also both lesbians. i love their music to death and post it here on sapphicisms occasionally since a lot of it is Very Gay but the endless gifsets i reblog to my main don’t have as much of a place here so i try to nip them out when i notice i’ve slipped up

id asked before but no one understood my question so i asked sarah and i got an answer that its possible so how i am going to headcanon my kids in a nonsburb au. dave and rose were identical twins (dfab) and originally had genes for heterochromia, when their egg split, dave got brown eyes that looked strangely red, and rose got blue eyes that looked purple.

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Types of Twins

Twins are more complex than just “identical” and “fraternal”!

Fraternal (or Sororal) Twins

When two eggs are released by the mother, and both are fertilized and implant successfully, two completely different gene sets develop into a fetus. The two eggs almost always develop their own placenta, and their own amniotic sac. These are scientifically known as dizygotic (di - two, zygote - egg) twins, and there’s a genetic basis to whether a female is predisposed to have them.

Identical (Monozygotic) Twins

When only one egg is released and fertilized, there’s a chance of identical twins forming. Unlike fraternal twins, there’s no genetic basis for the formation of identical twins, so it’s uncommon for families to have multiple sets of them. There are several types of monozygotic twins:

  • Dichorionic-Diamniotic Twins (DiDi)
    These twins have two (di-) chorions (which means they also have two placentas) and two amniotic sacs. They occur when splitting of the fertilized egg (embryo) occurs less than 72 hours after fertilization. Fraternal twins are also considered “DiDi”. Around 25% of identical twins are DiDi. These twins have the lowest mortality rate, at about 9%.

  • Monochorionic-Diamniotic (MoDi)
    These twins have one (mono-) chorion (meaning one placenta), but two amniotic sacs. This occurs when the embryo splits between 4 and 8 days after fertilization. Because they only have one placenta, there’s a risk of twin-to-twin transfusion syndrome. Between 60-70% of identical twins (and about 0.3% of all pregnancies) are MoDi.

  • Monochorionic-Monoamniotic (MoMo)
    “MoMo” twins share both their chorion and amniotic sac. They make up about 1-2% of all monozygotic pregnancies, and occur when the embryo splits between 9-12 days after fertilization. They have the highest mortality rate of all monozygotic twin pregnancies, with only 50-60% surviving to birth. In addition to twin-to-twin transfusion syndrome, the risk of one or both fetuses becoming entangled in the umbilical cords and cut off from nutrition can lead to significant disability even when both babies survive.

  • Conjoined Twins
    When twins separate later than 12 days after fertilization, the split is very rarely complete, and conjoined twins occur. In general, the later the split, the less complete the split is. They have the highest mortality rate among twin pregnancies.

“Mirror Twins”

When MoMo twins split between the 10th and 12th day after fertilization, they often develop into “mirror twins” - that is, they’re the inverse of one another. Things like dominant handedness (left vs right-handedness), dominant eye, dental development, and even the direction of their organs inside their body can be reversed. Not all MoMo twins that split during  this time period are “mirror”, but many are.

Illustrations:

The Practice of Obstetrics. Edited by Charles Jewett, 1901.

See also:

Conjoined female twins in the Nuremberg Chronicles. By Hartmann Schedel, 1440-1514.

Placentation diagram by Kevin Dufendach at Wikipedia

Don’t be mad cause i’m doing me better than you’re doing you. 

Models: Chris and Courtney
Brand: FLAVNT Streetwear
Photographer: yoomsters

Help me find my doppelganger!

So this photo set started circulating through ifunny a few weeks ago, and everyone though it was me.  So I decided to do a little side by side.

WHO

IS 

THIS

PERSON

I also decided to have a little fun with it too…

I NEED

TO FIND

MY LOST TWIN