Comparing Twins

Identical twins look so similar because identical twins have the same genetic makeup, meaning, the same DNA (same nitrogenous bases). This is because by they are fertilized by the same egg, making them identical.

There are a number of possible types of these births. These include thoracopagus, the most common, affecting 35% of all conjoined twin births, where the chest wall is shared, and often the heart. Pygopagus is another type, occurring in 19% of all cases, where the twins are joined at the buttocks. Two significantly less occurring patterns are ischiopagus, 6%, connected at the tailbone, and craniopagus, 2%, with a fused skull. Some other commonly occuring types include cephalopagus, with the upper torso and back of the cranium fused, and dicephalus, having two heads and necks connected to one body. Cephalopagus and craniopagus twins are rarely operated on, because the brain is such a delicate organ on which to operate, especially when shared brain tissue is involved. Other types include parapagus, a lateral fusion of the lower half of the body, and omphalopagus, joined frontally at the midsection. Finally there is parasitic twinning, where one twin is dependant upon the other for life, and often one is misformed, lacking organs or fully formed parts (www.twinstuff.com).

3. What is the difference between MZ and DZ twins? The difference between MZ and DZ twins is MZ twins are monozygotic twins which means that they are identical because they have mono (one) placenta. The DZ twins are dizygotic twins, they are fraternal twins and did not share the same placenta. DZ twins are not identical. MZ twins are genetically identical, DZ twins have only 50 percent of their genes in common. Some studies have shown that identical (MZ) twins raised apart and have never met have nearly identical behaviors. Identical (MZ) twins are much closer than fraternal twins. I personally have seen this because I am the mother of MZ twins. My boys are identical in every way. They are actually mirror image identical twins. Their hair is exactly opposite in the way that their hair lays in the back of their head. One has a cow lick in the front on the left side and the other has a widow’s peak on the left side in the front. One has a freckle on the back of his neck on the left side and the other has a freckle in the exact spot on the opposite side of his neck. When the boys started rolling, one rolled left and the other rolled right. When they started crawling, one crawled forward and the other backward. Their teeth

The biography Identical Strangers by Elyse Schein and Paula Bernstein is about twins that got separated at birth, and now are finding out there is another person in the world with their exact DNA. They were part of a study on separated twins. It was to see in nature versus nurture which one has more of an impact. (31-32) Identical twins were easiest to study because of their identical DNA. Scientists working on the study placed both girls in a family in which are very similar; therefore, they both have a brother that is a couple years older than them. They find out about the other twin, and Paula is having their

Parallel to this, the focus on genetics is Particularly convicted in twin studies, which establish a comparison between monozygotic twins that are identical and dizygotic twins, which are opposingly non-identical. This distinction can be identified in Torgersens study, which compared MZ and same sex DZ twins where one proband had an anxiety disorder, and it was discovered that such disorders were 5x more frequent in MZ twin pairs, who mutually shared identical genetics.

Monozygotic twins: Monozygotic twins are also known as identical twins. These twins start their life as one egg which is fertilized by one sperm and latter splits into two eggs much earlier in the gestational period. These are very rare and have no link to heredity. But studies reveal that only one of four conceptions of twins is identical. Therefore, it seems likely that any differences between twins will have to be caused by environment rather than by genetics.

1. What are identical twins? What explains any differences they may develop? Identical twins are twins that develop from the same fertilized egg. Differences in their environment are what explains any differences they may develop.

Twins, share a bond that no parent, child or sibling relationship can ever compare. There are two main types of twins, and these include: monozygotic (identical) twins and dizygotic (fraternal) twins, and they are compared by their emotional, behavioural, and cognitive similarities. (Robert Plomin, 1997). According to Social Issues Referencing, 2007, whereas Identical twins are formed from a single (mono) zygote and are genetic “carbon copies”, fraternal twins develop from two (di) separate zygotes, as a result of two eggs being fertilized by two sperms independently. (Social Issues Referencing, 2007, para. 8)

What would it be like to have a twin? This is a question people often ponder. People often say that they see someone that resembles someone they already know. It is almost like dejavu. "Twin" comes from the German word "twine" meaning "two together" (Nagy 1). Most people automatically think of two people who look just alike when they hear the word "twin". However, there is a lot more to twins than just looking alike. Twins are the most common type of multiple births. Many think there are only two types of twins, identical and fraternal; they often leave out conjoined twins. Twins are very unique and fascinating individuals because of their similarities biologically, physically, and psychologically.

Twins are born with the same genome and epigenome but the environmental factors that they are exposed to bring a difference in their epigenome. As twins grow they experience different things and they make distinct life choices which can make twins so different from each other.

Throughout history, across all cultures, people have been fascinated with twins. In addition to interest in the close emotional ties and biological similarities that twins may share, reports of special twin languages and twin extrasensory perception (ESP) help people to explore ideas of what it means to be human. How similar or different are they to each other? How important are genes and environment for development? Because identical twins share all of their genes, it is the environment—rather than genetics—that accounts for any differences between them.

Conjoined twins also known as Siamese twins are very rare, they only have a 1 out of 1,000 chance of happening. These twins are babies that are born physically attached to each other. When this happens, most twins are stillborn (die in the womb) or die shortly after birth. These types of twins can be diagnosed as soon as the first 3 months of the babies’ development using ultrasound. Conjoined twins that survive are mostly female, but more male twins form than females.

I observed a set of dizygotic or fraternal twins, Antonio and James, that had walked in, which were both males. I noticed that they were attached to their mother, which I had considered “normal” when thinking back to when my 15 year old daughter was that age. Even

There are two types of twins. One type of twins, called identical twins, is exact clones of each other. They share the same DNA and were made from a single split egg. More research as been done regarding these types of twins as they are the more remarkable kind. Since they are a genetic match, nature plays the

For years I have been fascinated by that mysterious quirk of nature called twins. In my family, there are several sets of identical twins, and I have always concentrated on their similarities. I did not realize that identical twins also have many differences. My identical twin cousins, Sue and Heidi, appear to be perfect mirror images. They love to dress alike. They can feel each other's pain. They sound alike and can complete each other's sentences. But upon taking a closer look, I have found that they are as different as day and night. Aside from Sue and Heidi's outward characteristics, they possess several distinguishing traits that allow them to be viewed as two separate, independent