As a student in a genetics lab you are assigned to create a

As a student in a genetics lab you are assigned to create a fly that has ebony body and vestigial wings. Vestigial is on the 2^nd chromosome and ebony is on the 3^rd chromosome. You are given two vials, one with ebony flies and one with vestigial flies. Select males and females to set up the necessary crosses that will create the fly you want. Keep in mind this may require several crosses Detail the crosses below and indicate the offspring for each cross.

Solution

Dihybrid cross

both ebony body and vestigial wings are autosomal traits

e ebony body

e+ wild type body

vg is vestigial wing shape

vg+ is wild type wing shape

vial can have ebony body eevg+vg+ or eevgvg+

test cross with eevgvg to select true parents

parents      eevg+vg+ X eevgvg

gametes      evg+             evg

offsprings    eevg+vg      ebony and wild type (only 1 type offsprings)

parents     eevgvg+ X eevgvg

gametes    , evg+, evg

offsprings     eevgvg (ebony and vestigial), eevgvg+(ebony and wild type) 2types of offsprings

so, those giving only 1 type of offspring are selected

similarly test cross of vestigial with eevgvg, those giving only 1 type of offspring are selected

selection of parents in vials (true breeds)

ebony body eevg+vg+

vestigial wing e+e+vgvg

crossing between parents

parents                 eevg+vg+   X e+e+ vg vg

gametes                  evg+               e+vg

F1 generation                 ee+vg+vg

crossing F1          ee+vg+vg   X    ee+vg+vg

gametes            evg+, evg, e+vg, e+vg+

F2 generation

selecting eevgvg and crossing the males and females with eevgvg

gametes evg evg

desired offsprings eevgvg

	e+vg	evg+	e+vg+	evg
e+vg	e+e+vgvg	e+evgvg+	e+e+vgvg+	ee+vgvg
evg+	ee+vg+vg	eevg+vg+	ee+vg+vg+	eevg+vg
e+vg+	e+e+vg+vg	ee+vg+vg+	e+e+vg+vg+	ee+vgvg+
evg	ee+vgvg	eevgvg+	ee+vgvg+	eevgvg