1. Monohybrid Crosses

2. What is a monohybrid cross?
A cross between individuals that involves one trait
A Punnett Square is a diagram used to show the probability that certain traits will be inherited by the offspring

4. Homozygous X Homozygous
Dominant crossed with recessive
All offspring are heterozygous
100% probability

5. Homozygous X Heterozygous
Dominant crossed with heterozygous
50% dominant
50% heterozygous
Recessive crossed with heterozygous
50% recessive

6. Heterozygous X Heterozygous
Probabilities
25% dominant
50% heterozygous
25% recessive

7. Genotypic Ratio .vs Phenotypic Ratios
Using the heterozygous cross:
Genotypic Ratio = GG:Gg:gg
1:2:1
Phenotypic Ratio = Green:White
3:1

8. Test Cross
When a dominant phenotype is observed and you want to know the genotype you perform a test cross
Cross the individual in question with one that is recessive
Ratio of offspring will tell you the genotype

9. Incomplete Dominance Two or more alleles influence the phenotype
Result is an intermediate phenotype

11. Co-Dominance
Both alleles for a gene are expressed in a heterozygous offspring kb24