|How are the roles of meiosis, fertilization, and
then mitosis different in the development of twins
versus identical twins?|
|Question Date: 2018-12-19|
Fraternal twins happen when two different
eggs are released by the mother, and each is
fertilized by a different sperm. They both have
the same mother, and the same father, but the
sex cells (produced by meiosis) that create them
are separate. The children then develop by
Identical twins is where the
already-fertilized embryo splits into two, each
becoming a separate individual, growing by
Meiosis created the sperm and egg cell in
the first place, but everything after that is
Twins can form in 2 ways:
1. The embryo can split in 2, and "identical
twins' are formed.
2. Two embryos can form and grow into fetuses at
the same time. Those are 'fraternal twins' -
siblings with the same birthday [brothers or
sisters or 1 of each].
So nothing happens til after fertilization.
Here's what I found about 'mitosis and
The only exception to this is in the case of
identical twins. Identical twins form from one egg
cell that has been fertilized by one sperm cell.
Because they form from the same 46 chromosomes, 23
from each parent, they do have the same genes.
Not all twins are identical.
meiosis and mitosis
In the case of identical twins, a single sperm
fertilizes a single egg. The
resulting zygote splits into two, and that’s how
two embryos are formed.
In the case of non-identical twins, two different
eggs are fertilized by two
different sperm. This means that the resulting two
embryos did not come
from the same egg. Thus, the twins will not be
identical. Meiosis and
mitosis proceeds in the same way once the zygote
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