Help to another pedigree

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mensamedlem
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Help to another pedigree

Post by mensamedlem » Fri Nov 20, 2009 12:42 pm

I need help to find the answer to the questions below this text:

1) Which genotypes do the persons have?

2) What proportion of the offspring from the individuals III-1 and III-2 are likely to have the disease?

3) What proportion of the offspring from the individuals III-6 and III-7 are likely to have the disease?

http://www.flickr.com/photos/[email protected]/4119434147/

Squares = males. Circles = females.
Yellow = sick. Green = healthy.

Can you help me?

mensamedlem
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Post by mensamedlem » Fri Nov 20, 2009 6:10 pm

My guesses are:

1) Which genotypes do the persons have?

All the sick individuals will be Aa and the healthy will be aa.

2) What proportion of the offspring from the individuals III-1 and III-2 are likely to have the disease?

Aa x aa = 1/2 = 50 percent.

3) What proportion of the offspring from the individuals III-6 and III-7 are likely to have the disease?

Aa x Aa = 3/4 = 75 percent.

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JackBean
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Post by JackBean » Sat Nov 21, 2009 2:13 am

The very first sick person should be probably AA, as both children are sick (but guessing from only 2 children is kind of not perfect;)
2 and 3 probably correct :)
http://www.biolib.cz/en/main/

Cis or trans? That's what matters.

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Post by mensamedlem » Sat Nov 21, 2009 8:02 am

Thank you!

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Post by mensamedlem » Sat Nov 21, 2009 8:33 pm

Is what I have written correct?

Figure 2: http://www.flickr.com/photos/[email protected]/4119434147/

The inheritance is dominant because genes partitions are not skipped and sick children have sick parents. It can not be x-linked since sick boys fathers are also sick. This is because the boy gets his Y chromosome through the father's sperm while the good x-chromosome from her mother's eggs.

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JackBean
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Post by JackBean » Sun Nov 22, 2009 1:40 am

you're too generalizing. What if the first one is ill homozygote and the second one is healthy but heterozygote?
http://www.biolib.cz/en/main/

Cis or trans? That's what matters.

mensamedlem
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Post by mensamedlem » Sun Nov 22, 2009 7:30 am

What can I write instead of this?

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JackBean
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Post by JackBean » Sun Nov 22, 2009 10:28 am

That it's dominant, because (your text) and because half of offspring is affected (if it was recesive, it would be only 1/4;)
http://www.biolib.cz/en/main/

Cis or trans? That's what matters.

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Post by mensamedlem » Sun Nov 22, 2009 11:34 am

Is my definition of that it cannot be x-linked correct?

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JackBean
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Post by JackBean » Sun Nov 22, 2009 12:45 pm

basically... I would say, that even ill men have healthy boys ;) Simpler and easier ;)
http://www.biolib.cz/en/main/

Cis or trans? That's what matters.

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Post by mensamedlem » Sun Nov 22, 2009 3:44 pm

Is my answer to the fact that it cannot be x-linked correct? Yes or no?

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JackBean
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Post by JackBean » Mon Nov 23, 2009 4:27 am

With closing both eyes, it's relativelly fine... but definitively not perfect ;)
The idea is fine, but not so much, how did you write it ;)
http://www.biolib.cz/en/main/

Cis or trans? That's what matters.

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