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Beginning with the work of Morgan, research on the fruit fly Drosophila melanogaster has been critical in our understanding of gene and chromosome inheritance. We looked at how Morgan determined that the gene that produces white eyes is located on the X chromosome. And we discussed how X-linked genes are inherited in males and females.Morgan and his colleagues also performed experiments to determine how far apart two linked genes are.
We need to learn about chromosomes and their genes because chromosomal abnormalities can lead to serious health problems! Both the number and the structural integrity of chromosomes are critical. Losing portions of chromosomes through deletions, or losing entire chromosomes, as in Turner syndrome, can remove thousands of genes. Mistakes like inversions and translocations, such as those that cause acute myeloid leukemia, can also disrupt important genes. Excess chromosomal regions resulting from duplications, or entire extra chromosomes, as in Klinefelter syndrome or Down syndrome, also cause serious health issues. That’s why mitosis and meiosis use such precise mechanisms to segregate chromosomes.
Since it is difficult to do experiments on people, scientists use other organisms to study many aspects of human diseases. By learning more about the genes and chromosomes of other organisms, we learn more about our own genes and chromosomes.
Copyright 2006 The Regents of the University of California and Monterey Institute for Technology and Education