Genetics questions

Rcjohnsen rcjohnsen at
Fri Mar 8 18:41:45 EST 1996

Reply to  asking 3 genetics questions:
 I doubt there's an answer to the first question about the number of genes
controlling eye color.  Eye color appears to dependent upon the number,
shape, and size of pigment granules in the iris as well as the type and
amount of pigment deposited on them.  The number of genes controlling this
is speculative.
 On the second question about the X chromosome necessary for viability,
the answer is, most definitely yes.  Research in Drosophila and mice where
0/Y zygotes can be produced experimentally shows that such zygotes die in
the early stages of zygotic division.  Hence, most scientists feel this is
true for 0/Y human zygotes too and you might find something more concrete
about it in a University or good community library with journals on in
vitro fertilization research.  The NY Academy of Sciences has published a
couple of volumes on this research.
 On the third question,  there is a lot of literature on the various
syndromes you had questions about.  I suggest you try searching
Searching OMIM Using Fill-In Forms

an online searchable database in human genetics.
Rcjohnsen at

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