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Why are some twins identical and some not?
The reason why some twins are identical and some are not starts in utero. Identical twins occur when one egg is fertilized and it splits to create two embryos. Nonidentical twins come from different fertilized eggs.
At the beginning of cell division DNA and the proteins associated with the DNA coil into a structure called an?
chromosome.
Doubled rod of condensed chromatin?
the chromosome
The Y chromosome is larger and carries fewer genes than the X chromosome?
No. The Y chromosome is much smaller than the X chromosome. There are only about 70 active genes on the Y chromosome and many more deleteriously mutated one. The X chromosome contains many more active genes and only crosses over marginally with the Y chromosome.
What are the causes of heredity diseases?
The causes of a hereditary disease is a missing chromosome, and extra chromosome. Like in Down Syndrome there is an extra chromosome 26.
Why do fraternal twins don't have to be of the same sex?
Unlike identical twins, fraternal twins come from two separate eggs each getting fertilized by a separate sperm. Now these sperms can both carry an X chromosome or a Y chromosome giving rise to fraternal twins of the same gender. But at times one could carry the X chromosome and the other could carry the Y chromosome resulting in twins of opposite gender.
Are the Sprouse twins mixed?
milk power
Are fraternal twins usually male?
Not usually, but always.Otherwise they would be sororal or mixed twins!
What gene or chromosome is affected by conjoined twins?
There is no genetic component that results in conjoined twins. They are created by an imperfect separation of identical twin concepti.
How can you have mixed sex twins on sims 2 PC?
**** you
What is Mariah Carey twins mixed with?
Mariah white and black nick is black the twins are half black and white
Do identical twins with opposite genders exist?
Yes, it's possible for a mutation in the chromosome to produce otherwise-identical twins with opposite genders. But generally no, identical twins have the same gender. (but fraternal twins have different genders just as often as any siblings)
Why can fraternal twins de different sexes while identical twins cannot?
To keep it simple and not get too technical, fraternal twins are from two eggs and two sperm that independently combine to produce a baby. Identical twins come from a single egg and sperm that divide to create two separate children. Gender is controlled by the males sperm and whether it contains the male genetic X chromosome. Since identical twins have the same sperm their genetic makeup is exactly the same (same egg and sperm used in development). Fraternal twins have two separate sperm and therefore it is possible one has the X chromosome and other does not.
Why are some twins identical and some not?
The reason why some twins are identical and some are not starts in utero. Identical twins occur when one egg is fertilized and it splits to create two embryos. Nonidentical twins come from different fertilized eggs.
Do twins get an extra chromosome from 1 parent?
No. Having an extra chromosome is actually a genetic defect. With twins, let's assume they are identical twins, the mother has one egg cell in the fallopian tube ready to be fertilized by a sperm cell. The sperm cell fertilizes the egg cell, but that egg cell then undergoes mitosis. All of the cell contents are duplicated and the cell divides into two. You now have 2 cells with the exact DNA which are twins. In the case of fraternal twins, the mother had two separate ova in her fallopian tubes and both were fertilized by two different sperm cells.
Which comedy starring Bette Midler told the story of twins mixed up at birth?
big buisness
Do conjoined twins have the same sex?
Yes. Conjoined twins are always identical (monozygotic) twins, and identical twins are always the same sex.There is a theoretical case where identical twins could be opposite genders, when the babies are female but in one of the females, a branch of one X chromosome breaks away; however, I don't believe this has ever been observed.
