90 likes | 311 Views
Dihybrid Crosses. Figuring out the probability of passing on 2 separate genes at the same time. Monohybrid Cross. Looking at a single gene. H = widow’s peak h = no widow’s peak Cross Hh x Hh. Results = 75% Widow’s, 25% none. Dihybrid Cross.
E N D
Dihybrid Crosses Figuring out the probability of passing on 2 separate genes at the same time.
Monohybrid Cross • Looking at a single gene. • H = widow’s peak • h = no widow’s peak Cross Hh x Hh Results = 75% Widow’s, 25% none
Dihybrid Cross • A cross between two individuals looking at 2 different genes at the same time. • For example: • H = widow’s, h = none • L = long 2nd toe, l = short 2nd toe • Cross 2 people heterozygous for both HhLl x HhLl
1. Figure out Gametes Using FOIL method HhLl x HhLl • First • Outside • Inside • Last HL HL D/D Hl Hl D/r hL hL r/D hl hl r/r
4. Figure out phenotype #s • D/D – Widow/Long = 9 • D/r – Widow/Short = 3 • r/D – None/Long = 3 • r/r – None/Short = 1