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Old 02-28-2006, 09:59 PM
teena teena is offline
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Join Date: Dec 2005
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GC special ed genetics class

Quote:
Originally posted by nikki1920
so if each parent had a dominant gene and a recessive gene, B and b respectively, the combos would be like this:

bb, BB, bB, Bb

expressed as:

bb = blue eyes
BB = brown eyes
bB = brown eyes (brown trumps blue)
Bb = brown eyes

So the child has a 1 in 4 chance of having blue eyes, and a 3 in 4 chance of having brown eyes.
***raising my hand****

But Mrs. 1920, for this example it wouldnt it be 1 in 4 because that assumes that the births is a single birth. But because they are twins doesnt that make the odd much higher?

ETA
Never mind I found my own answer.

"Fraternal twins develop from two separately fertilized ova. Since two sperm and two ova are involved, these twins are no more similar genetically than ordinary siblings. Like ordinary siblings, fraternal twins may be of the same or opposite sexes. They, too, have furnished psychologists with valuable data."

I need to get back in school, quickly.

Last edited by teena; 02-28-2006 at 10:04 PM.