1. Dihybrid Problems
Definition – Genetics Problems with two traits tracked at the same time
Try This:
Given B = brown hair, b = blond hair AND T = Tall while t = short.
BbTt = ______________ phenotype
Bbtt = ______________ phenotype
bbTT = ______________ phenotype
bbtt = ______________ phenotype
Brown, Tall
Brown, Short
Blond, Tall
Blond, Short

2. Arrow Rule Arrow Rule: BbTt
When drawing your sperm and egg for the 7 steps in this type of problem each:
Sperm contains __________ genes?
Egg contains __________ genes?
Predict the sperm or eggs possible for a critter of BbTt.
Arrow Rule: 2 2
BbTt
BT, Bt, bT, bt

3. Dihybrid gamete formation
What sex cells could be obtained from the genotypes below?
Bbtt: ___________, ___________, ___________, ___________
bbtt: ___________, ___________, ___________, ___________
BBTT: ___________, ___________, ___________, ___________
BbTt: ___________, ___________, ___________, ___________
Hint: repeated sperm or eggs can be crossed out.
Bt Bt bt bt
bt bt bt bt
BT BT BT BT
BT Bt bT bt

4. Dihybrid: Cross a totally heterozygous brown eyed tall girl with a heterozygous brown eyed homozygous tall guy.
Do together on board