Final answer:
The Philadelphia chromosome results from a translocation between chromosomes 9 and 22, creating a shortened version of chromosome 22 that is significant in the development of chronic myelogenous leukemia.
Step-by-step explanation:
The Philadelphia chromosome is an example of a chromosomal abnormality resulting from a specific type of translocation, specifically between chromosomes 9 and 22. This translocation causes a portion of chromosome 9 to be exchanged with a portion of chromosome 22, creating a shorter version of chromosome 22. Importantly, this abnormality is associated with chronic myelogenous leukemia (CML), as it results in the production of the BCR-ABL fusion protein, an oncogenic tyrosine kinase.
Given the provided options and definitions, the correct answer is b. a shortened version of chromosome 22 that results from a translocation. This is not an instance of aneuploidy, which involves a change in the total number of chromosomes. Instead, it is a structural change involving the exchange of genetic material between chromosomes.