Dihybrid Cross

Warm up Complete the Genetics Practice Problems worksheet You will have 8 minutes to complete and get stamped before we review

Dihybrid Cross Aladdin and Jasmine want to have a child. Aladdin is homozygous for brown hair and brown eyes. Jasmine is homozygous for black and black eyes. Perform a test cross and predict the possible genotypes and phenotypes for their offspring. (B- Black hair; b-brown hair) (E- black eyes; e- brown eyes)

Dihybrid Cross Step 1- Create a Key B: black hair b: brown hair E: black eyes e: brown eyes

Dihybrid Cross Step 2: Identify the parent genotypes Aladdin: homozygous for brown hair and eye bbee Jasmine: homozygous for black hair and eyes BBEE

Dihybrid Cross Step 2a- Number the parent alelles: Aladdin: b1b2e3e4 bbee x BBEE Aladdin: b1b2e3e4 Jasmine: B1B2E3E4 Aladin: 1-3 (be) 1-4 (be) 2-3 (be) 2-4 (be) Jasmine: 1-3 (BE) 1-4 (BE) 2-3 (BE) 2-4 (BE)

Dihybrid Cross Step 3a: Labeling the punnett square Aladin is on top of the box be be be be Aladin: 1-3 (be) 1-4 (be) 2-3 (be) 2-4 (be)

Dihybrid Cross Step 3b: label the side of the punnett square Jasmine : BBEE be be be be BE Jasmine: 1-3 (BE) 1-4 (BE) 2-3 (BE) 2-4 (BE)

Dihybrid Cross Step 4: Fill in all 16 boxes with the possible gametes from the cross Each box will have 4 letters or 2 traits be be be be Aladin: 1-3 (be) 1-4 (be) 2-3 (be) 2-4 (be) (BE) BEbe Jasmine: 1-3 (BE) 1-4 (BE) 2-3 (BE) 2-4 (BE)

Dihybrid Cross Step 5: List all possible genotypes and phenotype ratios be be be be BE BEbe, BEbe, BEbe , BEbe, BEbe, BEbe, BEbe, BEbe, BEbe, BEbe, BEbe, BEbe, BEbe, BEbe, BEbe ( 100% BEbe) BEbe

Dihybrid Cross Conclusion All 16 traits were BEbe, which is Heterozygous for Black Hair and Black eyes Genotype: 100 % BEbe Phenotype: Black Hair and Black Eyes Happily Ever After The End