CHAPTER 15

THE CHROMOSOMAL BASIS OF INHERITANCE

OBJECTIVES

1. Describe the contribution that Thomas Hunt Morgan made towards our current understanding of chromosomal inheritance.*
2. Explain why Drosophila melanogaster is a good experimental organism for genetic studies.*
3.Carry out Punnett square analysis using sex linked genes in both humans and Drosophila.
4. Describe sex determination in mammals.*
5. Describe the unique characteristics of the Y chromosome in humans.*
6. Explain why a recessive X-linked gene is always expressed in human males but not always expressed in females.*
7. Carry out a Punnett Square to explain sex inheritance.
8. Explain nondisjunction and describe the consequences.*
9. Distinguish between trisomic and monosomic chromosomes; sex linked and non sex linked disorders.*
10. Distinguish among deletions, duplications, translocations and inversions and give an example.*
11. Describe X- inactivation in females.
12. Understand the chromosomal inheritance patterns of other species, relative to mammal.

KEY TERMS

 Thomas Hunt Morgan, Drosophila melanogaster, wild type, mutant phenotype, autosome, sex chromosome, aneuploidy, nondisjunction, trisomic, monosomic, deletion, duplication, translocation, inversion, X inactivation, Barr bodies.