Dihybrid help

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

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Dihybrid help

Post by Trinity » Wed Jul 08, 2009 5:38 am

Thanks all
Last edited by Trinity on Sun Jul 12, 2009 3:40 am, edited 1 time in total.

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Post by kolean » Wed Jul 08, 2009 2:31 pm

Usually you put the individual allele for an answer, not the wording, except for the definition of your alleles. So for you use:

E for shell, EE or even Ee for spotted shells, and ee for grey colored shells
B for skin color, BB or even Bb for brown skin color, and bb for green skin color

a) F1 is the first progeny of the crossing, thus you cross a EEbb X EEBB,
you get the gametes for your Punnett Square: Eb (offspring turned parent) and EB (wild type parent) to get only EEBb.
(there is a possiblity that the green skinned spotted egg dragon could have been Eebb. Then you have the gametes Eb and eb, so you could end up with an EEBb or EeBb - same phenotype though).

b) phenotype is in words: spotted shells with brown skin

c) Genotype is the letters: EEBb (or possibly EaBb depending on the offspring parents second allele of being Eebb or EEbb - they both give the same phenotype).

d) gametes for the Punnett Square are Eb and EB.

Drawing of a Punnett Square:

Could be simple as:
********** Eb
EB****/ EEBB

********* Eb / eb
EB/** EEBb / EeBb

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