Dihybrid Crosses

1
Dihybrid Crosses

• Adding a Second Trait

2
Dihybrid Crosses

• Dihybrid crosses take into consideration two
  separate traits being inherited at the same time.

3
Dihybrid Crosses

• Each parent now has two sets of allelesone for
  each trait (Ex. TtPp x TtPp)

X
4
Dihybrid Crosses

• The Punnet Square will now be a large square
  separated into 16 boxes.

5
Dihybrid Crosses

• To determine possible gamete combinations, use
  the FOIL method (First, Outside, Inside, Last)

• TtPp
• First TP
• Outside Tp
• Inside tP
• Last - tp

T t P p
6
Testcross

• Testcrosses are used to determine whether or not
  an organism is pure bred.