In Drosophila Melanogaster, fruit flies, there are a number of simple recessive
ID: 8040 • Letter: I
Question
In Drosophila Melanogaster, fruit flies, there are a number of simple recessive mutations on the autosomes. They include curly wings (cy) and sapia eyes (se). The "wild" type, without any mutations, is represented by ++. Imagine there was a parental cross of homozygous curly wings but wild type eyes (cycy++) by homozygous wild type wings with sepia eyes (++sese). What would the genotype and phenotype of the F1 generation be? Assume F1 generation were crossed to produce F2 GENERATION. then draw a punnett square showing gametes from F1 generation could produce, and combinations as a result of fertilization. what percentage of phenotypes would you expect. PLEASE ANSWER , I totally understand di and trihybrid crosses but how am I supposed to do a punnett sqaure on this!? please explain in detail and draw square.Explanation / Answer
a parental cross of homozygous curly wings but wild type eyes (cycy++) by homozygous wild type wings with sepia eyes (++sese
++cycy x sese++,
where ++ is mutation-free wild-type,
cy------------------curly wings-----------------recessive
Cy-----------------------wild-type wings ---------------dominant
se----------------------sepia eyes ---------------recessive
Se-----------------------wild-type eyes -------------dominant
++cycy x sese++,
Can be shown as follows
SeSecycy x seseCyCy
Secy seCy-------------------gametes
Secy seCy ------------------------ F1 generation ---------- heterozygoytes
Secy seCy -----------------looks like wild organism
Secy seCy x Secy seCy
Secy , seCy SeCy secy ---------FOUR TYPES OF GAMETES
SeCy
Secy
seCy
secy
SeCy
SeCy SeCy
wild-type eyes, wild-typewings
SeCy Secy
wild-type eyes, wild-typewings
SeCy seCy
wild-type eyes, wild-typewings
SeCy secy
wild-type eyes, wild-typewings
Secy
SeCy Secy
wild-type eyes, wild-typewings
Secy Secy
Secy seCy
wild-type eyes, wild-typewings
secy Secy
seCy
SeCy seCy
wild-type eyes, wild-typewings
Secy seCy
wild-type eyes, wild-typewings
seCy seCy
secy seCy
secy
SeCy secy
wild-type eyes, wild-typewings
secy Secy
secy seCy
secy secy
1 sepia eyes, curly wings
THE RATIO IS 9:3;3:1
9 wild-type eyes, wild-typewings:
3 wild-type eyes, curly wings:
3 sepia eyes, wild-typewings:
1 sepia eyes, curly wings
SeCy
Secy
seCy
secy
SeCy
SeCy SeCy
wild-type eyes, wild-typewings
SeCy Secy
wild-type eyes, wild-typewings
SeCy seCy
wild-type eyes, wild-typewings
SeCy secy
wild-type eyes, wild-typewings
Secy
SeCy Secy
wild-type eyes, wild-typewings
Secy Secy
Secy seCy
wild-type eyes, wild-typewings
secy Secy
seCy
SeCy seCy
wild-type eyes, wild-typewings
Secy seCy
wild-type eyes, wild-typewings
seCy seCy
secy seCy
secy
SeCy secy
wild-type eyes, wild-typewings
secy Secy
secy seCy
secy secy
1 sepia eyes, curly wings