Other Chromosomal Abnormalities

Other Chromosomal Abnormalities - Other Chromosomal...

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Other Chromosomal Abnormalities Deletions Deletions are fragments of chromosomes that are missing. They are usually lethal when homozygous and cause abnormalities when heterozygous. Radiation, viruses, chemicals, and unequal crossing-over may cause them. Cri du Chat Syndrome Cri du chat syndrome is due to a deletion of a portion of chromosome 5. Cri du chat individuals are mentally retarded. "Cri du chat" is French for "cry of the cat". The infants cry sounds like a cat. Duplication A chromosome segment that is repeated is called a duplication . It can be due to unequal crossing over which produces a deletion on one chromosome and a duplication on the other. Often, multiple copies of genes from duplication can mutate without harming the individual because they still have one good copy of the gene. This type of mutation may be a source of variation for species. For example, the gene for human globin has given rise to several different genes that produce similar types of proteins. The different globins produced by these genes have
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This note was uploaded on 01/04/2012 for the course BSC BSC1005 taught by Professor Orlando,rebecca during the Fall '10 term at Broward College.

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Other Chromosomal Abnormalities - Other Chromosomal...

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