rosborne979 wrote:Gelisgesti wrote:In sexual reproduction, a child gets half its genes from its mother (in her egg) and half from its father (in his sperm).... This combination of genes is a fundamental basis for human variation and diversity.
Yes, we know this already. The point is, that when identical twinning occurs, the single genetic cell you are talking about splits into two distinct identical genetic structures; an even better replication than can currently be accomplished with cloning (
See Telomeres).
How about using the whole quote just to be honest ....OK?
Quote:In sexual reproduction, a child gets half its genes from its mother (in her egg) and half from its father (in his sperm).... This combination of genes is a fundamental basis for human variation and diversity. In the case of clonal reproduction, all of the cloned child's genes would come from a body cell of a single individual. If I had a clone it would not be my brother, it would be a copy of me.
Had you done that everyone could see that a clone, asexually reproduced .... has only the donor's genes, not one each from the mother and the father.
This is tough stuff for conjecture or winging, you really should respect the forum by trying to be at least a bit more versed n the subject. While thirty five years in medicine hardly qualifies me as a genetic expert, I have tried to learn what I could.
For instance, not all twins are identical ..... it' true....
How Twins Are Made!
Multiple births in human beings arise either from the simultaneous impregnation of more than one ovum or from the impregnation of a single ovum that divides into two or more parts, each of which develops into a distinct embryo. A woman normally releases a single egg from an ovary about once a month. Once the egg is fertilized by a sperm cell, it is called a zygote. It is then implanted in the wall of the uterus where it develops until birth. Occasionally, two or more eggs are released.
Basically there are two types of twins. Some are so similar that they are called identical twins while others are no more similar than ordinary siblings and are called non-identical, or fraternal twins.
How Fraternal Twins Are Made!
Well, unlike identical twins which arise from the splitting of a single
fertilized egg, fraternal twins arise from two different fertilized eggs
(i.e. each fertilized by a different sperm). These separate fertilized eggs
have the same genetic relatedness as ordinary siblings (brothers and
sisters). Thus only half of the genes in the twins are identical.
Basically fraternal twins are no different than two siblings born
several years apart. It was just that 2 eggs were released into the
fallopian tube of the female instead of one.
How Identical Twins Are Made!
Identical twins are formed when one fertilized egg splints in two.