predict outcome of a cross between 2 F2 PLANTS

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ptcheng416
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predict outcome of a cross between 2 F2 PLANTS

Post by ptcheng416 » Tue Jan 11, 2011 12:33 am

After a dyhibrid cross between two heterozygous plants (F1 progeny) to produce 16 F2 progeny, I need to know
how would you predict the outcome of a cross between any two F2 progeny without giving their genotypye or phenotype?

magicsiew
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Post by magicsiew » Tue Jan 11, 2011 7:21 am

Again use a punnet square... but will be longer and more complicated... so do it slowly to avoid mistake...

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JackBean
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Post by JackBean » Tue Jan 11, 2011 9:27 am

it won't be more complicated. He just need to do crosses for each combination ofF2 plants (there are 4 genotypes, so 16 combinations, some of them will be duplicated) and probably involve the probability that this cross will happen (like this genomes form 25 and 50%, so the cross will occur in ...% of cases)
http://www.biolib.cz/en/main/

Cis or trans? That's what matters.

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Kezzer
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Post by Kezzer » Tue Jan 11, 2011 9:27 am

I'm pretty sure I remember doing one of these at undergrad and hated it!!
If it is the tri hybrid cross outcome that you're looking for then as magicsiew said they are longer and more complicated so make sure you check through it to make sure you've got the correct outcome.
For a di hybrid you expect to see 9:3:3:1.
If it is the outcome of a tri hybrid that you're after I'm pretty sure you'll be looking for 27:9:9:9:3:3:3:1 as the result but I'm not certain since I did this a while back!
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Kezzer
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Post by Kezzer » Tue Jan 11, 2011 9:29 am

If it's just a standard cross of F2 generation i.e genotype phenotype AaBb then its the same result as a dihybrid cross.
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JackBean
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Post by JackBean » Tue Jan 11, 2011 9:36 am

he's talking about dihybrid, so no need for more complicated trihybrid ;)

and now I'm looking, that he wants only prediction, so no Punnet is actually needed.
http://www.biolib.cz/en/main/

Cis or trans? That's what matters.

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Kezzer
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Post by Kezzer » Tue Jan 11, 2011 9:46 am

Yeh wasn't sure what he wanted so mentioned the trihybrid and dihybrid so he could pick out the one he wanted lol
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