1. The Chromosomal Basis of Inheritance
Relating Mendelism to Chromosomes
Sex Chromosomes
Errors and Exceptions to Chromosomal Inheritance

2. Relating Medelism to Chromosomes
Mendelian inheritance has its physical basis in the behavior of chromosomes during sexual life cycles
Morgan traced a gene to a specific chromosome
The importance of fruitflies
Discovery of sex linkage

3. Sex Chromosomes
Chromosomal basis of sex varies with the type of organism
Sex is determined by the presence or absence of special chromosomes
Humans: XX= female XY = male

5. Sex Chromosomes Have a unique pattern of inheritance
1) X-inactivation-formation of
Barr Bodies
2) Sex-linked disorders in humans-
hemophilia and color blindness

6. Errors and Exceptions in Chromosomal Inheritance
Changes in chromosome number aneuploidy and polyploidy
Changes in chromosome structure deletions, duplications, translocations, and inversions

8. Human Chromosomal Disorders
Sex Chromosome Disorders:
Klinefelters, Turners, extra Y, triple-X syndromes
Autosomal:
Down (21), Patau (13) Edwards (18) syndromes

10. Phenotype and Gene Source
Some phenotypes are dependent upon parental source
Genomic imprinting
Fragile X syndrome