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difficult biology problem, appriciate ANY help!

Genetics as it applies to evolution, molecular biology, and medical aspects.

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difficult biology problem, appriciate ANY help!

Postby moriahlikesbeer » Tue May 15, 2012 4:11 pm

[size=150]٩(๏̯͡๏)۶This is a very difficult question I’ve come across in my studies I would sincerely appreciate anyone’s assistance. This is coming from an 11th – 12th grade exam not in any particular textbook.
(THE QUESTION/PROBLEM*** Human beings are very complex and so is human genetics. There are some traits in humans determined by a single gene such as tongue rolling. Some people are able to roll their tongue up at the edges; others are not. Is this a dominant or recessive trait? Study this pedigree which shows the appearance of this trait in three generations of a family. Image
From this chart would you conclude the trait to be dominant or recessive? Why? From the pedigree would you conclude the male in the first generation to be heterozygous or homozygous? Why?
(MY CONCLUSION *** I have come to the conclusion that it is impossible for the of offspring of the first generation to have a ratio of 3 : 4 tongue rollers if the dominant trait always shows over the phenotype of a recessive trait. Also my problem solving processes of making many punnett squares leads me to believe if the male has a dominant tongue rolling trait then the offspring have either a 100% or 50% chance of being able to roll their tongue. If the gene is recessive then the female must also have the trait BUT the pedigree provided shows parental female as an empty circle which means she does not have the trait…. )
Last edited by JackBean on Tue May 15, 2012 4:51 pm, edited 2 times in total.
Reason: no need to shout on us!
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Postby Darby » Tue May 15, 2012 4:46 pm

You're confusing probabilities with actualities...
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Re:

Postby moriahlikesbeer » Wed May 16, 2012 7:47 am

Darby wrote:You're confusing probabilities with actualities...


You mean "what might happen mathmatically" and "what actually does" ?

Well I need to explain why what has happened, happened that is why I'm calculating probability....

Can you explain the pedigree?
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Postby moriahlikesbeer » Wed May 16, 2012 4:46 pm

I would like this topic deleted. I found my answer at http://www.reddit.com/r/biology/comment ... _pedigree/
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