The science of twins (Identical, Fraternal, and conjoined) By: Ella Stimson, Hanna Hudson, and Isabella Smith 4th Period  

Twins  What are twins? The birth of more than one offspring at a time is called a multiple birth, otherwise known as twins.  How do twins become conjoined? Twins are conjoined based on stem cells in the way they behave during the very earliest stages of fetal development.

Sets of Twins & Differences Between Them  What is the difference between identical and fraternal twins?  The only difference between identical and fraternal twins is that fraternal twins are born in two separate placentas and identical twins always share a single placenta.   How many sets of twins exist currently worldwide? Around 125 million sets of twins exist worldwide and about 1/3 are identical twins.

Features & Separations  How are conjoined twins separated? At birth, they are usually separated by surgery. It is easier surgery if they are conjoined by ligaments and bones, but harder if they share organs.   What are the main features identical twins have in common? Identical twins share the same blood type, appearances, gender, and biochemistry detail. Their fingerprints are slightly different as well. 

Personalities & Similarities  Do twins tend to have similar or different personalities? One twin is usually more dominant and outing going than the other.   Which is more common: fraternal or identical twins? Identical twins are more common because though they are rare, it is more natural and likely to happen.

Conjoined Twins What has to happen for twins to become conjoined? For this to happen, when the egg splits, sometimes it doesn't split all the way. This causes the babies to form and grow together.  On average, how long do conjoined twins live? Conjoined twins don't live as long. The surgery is to really save only one twin,  but it's possible both can survive.

DNA & Diseases    What is the difference of what has to happen in the DNA to produce identical or fraternal twins? If the egg splits they are identical twins and if there are two eggs that are fertilized, they become fraternal twins.   Do diseases effect fraternal or identical twins more? Diseases are most likely to occur in both twins that are identical because they came from the same egg. This means that it's genetics since they share genes or it's the environment  that cause numerous diseases. Ex: Alzheimer, mental diseases, cancer, Autism, strokes, diabetes, etc.

Development & Birth    On average, how much time is in between the births of twins naturally or by C- Section? Twins born naturally takes about 12-15 minutes and C- Section can be a minute or less.  Do twins develop at the same rate? (Puberty)  Since they were in the womb together, it is more common for them to develop at the same rate. 

Features  What is the most common feature fraternal twins don't share with each other? They do not share the same gender and normally don't have the same appearances. 

Multiple Births Statistics Key: Red- Total Number of Multiple Births  Yellow- Number of Twin Births Blue- Number of Triplet Births Purple- Number of Quadruplets Births Green- Number of Quintuplets and Other Higher Order Multiples  Multiple Births Statistics 139,862 133,155 Number of Multiple Births  Data Source Citation: “Multiple Births Statistics.” Multiples of America - Connecting + Supporting Multiple Birth Families, www.multiplesofamerica.org/research-2/multiple-births-statistics/.   4,123 228 24 Types of Multiple Births 

Works Cited Page   Insights From Identical Twins, learn.genetics.utah.edu/content/epigenetics/twins/.   “Multiple Births Statistics.” Multiples of America - Connecting + Supporting Multiple Birth Families, www.multiplesofamerica.org/research-2/multiple-births-statistics/.   “Log In.” Britannica School, school.eb.com/levels/middle/article/multiple-birth/275978#205002.toc.   "Conjoined Twins." Galileo Teen, eds.a.ebscohost.com/eds/detail/detail?vid=1&sid=23edc2b7-6ba7- 4339-b1d3- ca150f99e58e%40sessionmgr4010&bdata=JnNpdGU9ZWRzLWxpdmUmc2NvcGU9c2l0ZQ%3d%3d #AN=89404474&db=ers. Accessed 24 Jan. 2018.  "Multiple Births." Britannica: Middle School, school.eb.com/levels/middle/article/multiple-birth/275978. Accessed 24 Jan. 2018.                                                                  

Conclusion      Many scientists are looking for more ways to separate conjoined twins and prevent conjoined twins from happening in the first place. I predict that genetic engineering will take place in the future and find ways to separate the placentas before the twins become conjoined. Scientists have been studying conjoined twins and how they become conjoined. According to Britannica Middle School, it states, "Scientists are researching more ways to prevent conjoined twins." This describes the future of conjoined twins. Many newborn babies are passing away due to this rare problem. This proves my opinion of the future of conjoined twins.