1. Test Cross Used to find the true genotype of a plant or animal that is dominant. They could be homozygous dominant (RR) or heterozygous dominant (Rr) we don’t know until we perform the cross.Used to find the true genotype of a plant or animal that is dominant. They could be homozygous dominant (RR) or heterozygous dominant (Rr) we don’t know until we perform the cross. They are crossed with a homozygous recessive individuals (rr)They are crossed with a homozygous recessive individuals (rr)

3. Modern Genetics What Mendel didn’t know: About genes and chromosomes

4. What Mendel didn't know Polygenic Inheritance – more than one gene controls a trait Polygenic Inheritance – more than one gene controls a trait Codominance Incomplete Dominance Linked Genes Sex-linked traits/ genes

5. Co-Dominance vs. Incomplete Dominance Incomplete dominance Co-dominance

6. Co-Dominance vs. Incomplete Dominance

7. Incomplete Dominance: phenotype of heterozygous is different than that of the homozygous dominant or recessive Both the 'dominant' and recessive alleles are expressed, resulting in a blended/mixed phenotype in the heterozygous organisms

8. Codominance - two alleles are equally dominant Both alleles when present are expressed Fur color in rabbits both black and brown or black and white are shown Blood Type – AB – both alleles A and B are expressed

9. Incomplete Dominance

11. Linked Genes Law of independent assortment – chromosomes sort independently NOT genes, they could go to either end/pole during segregation Genes/Traits that are located on different chromosomes will sort independently, just like the chromosomes they are on Genes/Traits that are close by on the same chromosome will always go together to the same pole/end – they sort together, segregate together

12. Linked Genes – Chromosomes Sort Independently NOT Genes What type of gametes will this pea plant produce? YyRr Y-yellow green seeds; y – green seed R-round seed; r – wrinkled seeds

14. Linked Genes are inherited together BECAUSE they are on the SAME chromosome and CHROMOOSMES, not genes sort independently during MEIOSIS

15. Sex-linked genes – genes that are on the X chromosome Y chromosome is small, very few genes X chromosome – many genes The traits are controlled by female parent because she gives the male his X chromosome The traits are controlled by female parent because she gives the male his X chromosome XX – female XY – male

16. Mothers and daughters are carriers, son's are affected. WHY?

17. X-linked Diseases Most are recessive – only males are affected, females carriers hemophilia color blindness Few are dominant – both males and females are affected Rett syndrome Fragile X syndrome