Which phenotypes represent the single cross overs (SCOs)?

C

chuottuan2004

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In the fruit fly, Drosophila melanogaster, a sable (s, black body) female fly is mated to a male that is garnet (g, pinkish eyes) and forked (f, forked bristles).
Phenotypically wild type F1 female progeny were mated to fully homozygous (mutant) males and the following progeny were observed.
Sable 4076
garnet, sable 5
garnet, forked 4154
wildtype 52
sable, forked 850
forked 7
garnet, forked, sable 43
garnet 813
TOTAL 10,000
Which phenotypes represent the single cross overs (SCOs)?
garnet, forked
garnet and sable/garnet/forked
sable/garnet, forked
sable/forked, garnet, wildtype, sable/garnet/forked
sable, garnet/forked

After you have determined the order of the genes, which gene is in the middle?
f
s
g

What are the map distances between the three genes?
sable - forked: 1 m.u.
garnet - forked: 16.7 m.u.
sable - garnet: 17.7 m.u.

sable - forked: 1 m.u.
garnet - sable: 16.7 m.u.
sable - garnet: 17.7 m.u.

sable - garnet: 1 m.u.
garnet - forked: 16.7 m.u.
sable - forked: 17.7 m.u.

sable - garnet: 1 m.u.
sable - forked: 16.7 m.u.
garnet - forked: 17.7 m.u.

What is your observed value for DCOs? ________
What is your expected value for DCOs?_________
16.7, 12
12, 16.7
5, 7
Cannot be determined from the data table.
 
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