There are more twin babies being conceived today than there have been since the 1980s. “One in 30 babies born in 2009 was a twin (a 76% increase since 1980)” (Goldman, L. Web source). Twins are born in different varieties. They can be fraternal or identical. Identical twins can be either both brothers or both sisters. If they are sister and brother, we say they are fraternal. Fraternal twins are twins who are not alike. Another term for fraternal twins is dizygotic. "...the mother gives two eggs which are each fertilized in the uterus by two different sperm from the father" (Baby2see, web source). Identical twins are genetically identical. Another term for identical twins is monozygotic. "...an egg (zygote) from the mother is fertilized by a sperm from the father, then very early in development the embryo divides and two fetuses grow" (Baby2see, web source). “Monozygotic twins are always the same sex, except in extremely rare cases of chromosomal abnormalities” (Prindle Fierro, source P. Web.) Whenever you see identical twins, they are either boy/boy or girl /girl. Identical twins are rarely seen. Many people assume that identical twins are similar in every way. “For a long time, identical twins were believed to be identical to a ridiculous degree. , identical twins were said to have the same number of hairs on their heads, although no mathematician is cited as having done the counting. However, everyone believed that such a thing was possible, and these beliefs persist today! 'today' (Gaddis, Vincent and Margaret, 1972, p. 11) It would be amazing if someone took time out of their day just to count if twins had the same...... middle of paper. .... gain sons at twenty-five day intervals. Similar twins have also been reported in Bengal, born forty-five days apart. An Australian mother gave birth to her twins, born fifty-six days apart. However, the record number of days between births appears to have occurred in 1846 in Strasbourg, France, an interval of 137 days. On April 30, a baby was born, but the twin did not appear until September 13” (Gaddis, Vincent and Margaret, 1972 (pp. 35-36). It is possible for pregnant women to lose a twin during pregnancy. 'a miscarriage but still carry a child. The second child came to term without any damage. "It is not known whether all of these twins born remotely were identical or fraternal. these twins are all “ordinary” in the sense that they were carried in one womb” (Gaddis, Vincent and Margaret, 1972 (pp. 35-36). Twins are formed in various ways..