They are always of the same sex, and are monozygotic or MZ twins (mono = one;
... For IVF deliveries, there are nearly 21 pairs of twins for every 1,000. ... to be the
same sex, while non-identical ...
Identical twins are almost always the same sex, but surprisingly there are a tiny
number of boy-girl monozygotic twins. They result from an egg ...
Although discordant karyotypes are known in identical twins, cases involving ...
as DSS/NR0B1, duplication of which can disrupt the male-determining pathway,
I have a twin sister. To answer about being twins of opposite genders, we have
always caught ... This is hard enough while not being a twin, but can become
even more complicated .... Why are there so few identical twins of opposite
Any parent of identical twins will tell you - there is no such thing as identical. ...
There have been 3 - 5 documented cases of opposite sex identical twins. This
Jul 11, 1999 ... Truly, none of the twins is genetically identical as they have a different
complement of X/Y chromosomes. Their sex chromosomes differ, but ...
Oct 1, 2015 ... And male/female twins certainly don't look identical! ... The result can be a MZ
twin pair of opposite sexes. ... Second example: There could be a glitch in
copying sex chromosomes during the formation of sperm or egg cells, ...
Identical twins are always the same sex and blood type. Identical ... They can be
of opposite sex. ... For identical twins, there is only one egg and one sperm.
Sep 15, 2012 ... And how does that affect their adult romantic relationships? ... Opposite-sex twins
– boy-girl twins – fascinate me. ... an opposite-sex twin herself and believes that
these pairings are less visible than identical or same-sex twins.
Can fraternal twins look so similar that they are mistaken for identical? ....
Identical twins are always the same sex; they usually are the same height, weight
and ... teeth eruption; Some mirror image twins cross their legs opposite each