6. Chromosomal Variation

A person has a WT chromosome with the following segments. A B C • D E F G H. Which of the following shows how the chromosome would look after an insertional duplication?

A person has a WT chromosome with the following segments. A B C • D E F G H. Which of the following shows how the chromosome would look after an tandem duplication?

How do we know that the mutant Bar-eye phenotype in Drosophila is due to a duplicated gene region rather than to a change in the nucleotide sequence of a gene?

From the following list, identify the types of chromosome changes you expect to show phenotypic consequences. duplication

A pair of homologous chromosomes in Drosophila has the following content (single letters represent genes):

Chromosome 1RNMDHBGKWU

Chromosome 2RNMDHBDHBGKWU

What term best describes the unusual structure that forms during pairing of these chromosomes?

Discuss Ohno's hypothesis on the role of gene duplication in the process of evolution. What evidence supports this hypothesis?