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Biology-Related Homework Help Genetics and Developmental Biology Topic started by: 601078493 on May 7, 2012



Title: how do i solve a trihybrid cross?
Post by: 601078493 on May 7, 2012
given the male has the alleles  AabbCC and the female has AabbCc

how would iset this up on a punnet square and solve it


Title: how do i solve a trihybrid cross?
Post by: JulianDavis on May 7, 2012
Don't use a huge Punnett square!  Use a Branch diagram.

First, make three Punnett square for the individual traits:

Aa x Aa = 1/4 AA  1/2 Aa   1/4 aa
bb x bb = all  bb
CC  x Cc = 1/2 CC and 1/2 Cc


Second, branch diagram (remember all of the b's will be bb)

AA  bb  CC (1/4 x 1 x 1/2 = 1/8)
AA  bb  Cc  (1/4 x 1 x 1/2 = 1/8)
Aa  bb  CC  (1/2 x 1 x 1/2 = 1/4)
Aa  bb  Cc  (1/2 x 1 x 1/2 = 1/4)
aa  bb  CC  (1/4 x 1 x 1/2 = 1/8)
aa  bb  Cc  (1/4 x 1 x 1/2 = 1/8)