Non identical twins are formed when the mother releases two eggs and both those eggs are fertilised. hope this helps :)
Identical twins develop from a single zygote that splits into two embryos during early development. Therefore, only one zygote is needed to form identical twins.
Two individuals that develop from the same zygote are called identical twins. If they develop from two separate zygotes, they are fraternal.
Identical twins, or monozygotic twins are formed from one zygote. This is usually a result of damage to the embryo that causes it to split into two. If both halves are big enough to survive and the split has happened early enough on then two badies sharing one amniotic sac, one placenta and the same DNA will be born.
A zygote is the initial cell developed through sexual reproduction and formed when two gametes come together. In other words, a zygote results when the female egg is fertilized. After rapid cell division, it eventually becomes an embryo.
It depends on the type of twins If It was identical (monozygotic) twins, one egg is fertilized (As you can see, identical twins have similarity in phenotype (the observable characteristic of an organism) because of development of one zygote divided into two embryos) but if it was non-identical twins, two eggs or more (such as triplets or quadruplets) are fertilized. The twins have differences in phenotype
Identical twins born with their bodies joined at some point and having varying degrees of duplication, a result of the incomplete division of the zygote from which the twins developed. Also called diplosomia.
Identical twins develop from a single zygote that splits into two embryos during early development. Therefore, only one zygote is needed to form identical twins.
Non identical twins.
Two individuals that develop from the same zygote are called identical twins. If they develop from two separate zygotes, they are fraternal.
identical twins are formed when one sperm fertilizes a single ovum and the zygote divides into two in the initial stages of cleavage of the zygote. then, the two parts of the same zygote develop independently. fraternal wins are formed when two sperms fertilize two different ova.
WHENE the division of the zygote is not complete,is pairs of siamese twins who maybe joined at the buttocks,chest,neck.
Twins can be identical or fraternal (monozygotic or dizygotic). For identical twins, one sperm fertilizes an egg. The zygote divides into two identical embryos. For fraternal twins, two separate eggs are fertilized. They both implant on the uterine wall, forming two zygotes.
It is possible to have twins through in vitro fertilization, but "monozygotic" or identical twins are just a fortunate accident of nature which happens when a zygote splits.
Monozygotic
Identical twins or triplets.
Identical twins.
With identical twins, one egg (zygote) from the mother is fertilized by one sperm from the father, and then very early in development the embryo splits and two fetuses grow. Spontaneous division of the zygote into two embryos is not considered to be a hereditary trait, but rather a spontaneous or random event. If the zygote splits very early (in the first 2 days after fertilization) they may develop separate placentas (chorion) and separate sacs (amnion). These are called dichorionic, diamniotic (or 'di/di') twins. While all fraternal twins are 'di/di', this occurs 20 - 30% of the time in identical twins. Most of the time in identical twins the zygote will split after 2 days, resulting in a shared placenta, but two separate sacs. These are called monochorionic, diamniotic ('mono/di') twins.These twins are very similar genetically, and share a single afterbirth. Very occasionally, twins will also share the same sac (fluid cavity). In about 1% of identical twins the splitting occurs late enough to result in both a shared placenta and a shared sac. These are called monochorionic, monoamniotic ('mono/mono') twins.