Tuesday, October 03, 2006


One like daddy and another like mommy

Everyone says all females have that maternal instinct. I've always wanted to be a mommy. When I heard there were twins in the family, I couldn't wait to get my hands on a couple. Specially after reading about the Weasely twins and the mischief they create.

Twins are two individuals who have shared the uterus during a single pregnancy and are usually, but not necessarily, born in close succession. Due to the limited size of the mother's womb, multiple pregnancies are much less likely to carry to full term than singleton births, with twin pregnancies usually lasting around 34 to 36 weeks. Since premature births can have health consequences for the babies, twin births are often handled with special precautions.

There are five variations of twinning that occur commonly in the world. The three most common variations are all fraternal: (1) boy-girl twins are the most common result, at about 40% of all twins born; (2) girl fraternal twins; (3) boy fraternal twins. The last two are identical: (4) girl identical twins and (5) (least common) boy identical twins.

Fraternal twins (commonly known as "non-identical twins") When two eggs are independently fertilized by two different sperm cells, fraternal twins result. Like any other siblings, have a very small chance of having the exact same chromosome profile, but most likely have a number of different chromosomes that distinguish them. Like any other siblings, fraternal twins may look very similar, particularly given that they are the same age.

However, fraternal twins may also look very different from each other. They may be a different sex or the same sex. Mixed-race twins, or twins born to parents of mixed racial origin, can vary considerably in their skin colouration and other features.

Identical twins occur when a single egg is fertilized to form one zygote (monozygotic) which then divides into two separate embryos. This is not considered to be a hereditary trait, but rather an anomaly that occurs in birthing at a rate of about 1:150 births worldwide, regardless of ethnic background.

Identical twins are genetically identical (unless there has been a mutation in development) and they are the same gender. (On extremely rare occasions, an original XXY zygote may form monozygotic boy/girl twins by dropping the Y chromosome for one twin and the extra X chromosome for the other.) They generally look alike. Fine physical details such as fingerprints will differ. As they mature, identical twins often become less alike because of lifestyle choices or external influences. Genetically speaking, the children of identical twins are half-siblings rather than cousins.

Studies have shown that identical twins reared in different environments share similar personality traits, mannerisms, job choices, attitudes, and interests. These findings add to the belief that many behaviors are derived from genes.

I hope life blesses me with fraternal twins.
One like daddy and one like mommy.

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