Other Chromo - because they still have one good copy of the...

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Other Chromo somal 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
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Unformatted text preview: 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 very similar amino acid sequences. An example of a family of genes that have been produced by duplication is the beta globin family. This family contains five functioning genes and a pseudogene. Epsilon globin G-gamma globin A-gamma globin delta globin beta globin a pseudogene All of these genes have similar amino acid sequences due to their evolution from the same ancestral gene. Some families of genes contain hundreds of genes....
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This note was uploaded on 12/15/2011 for the course BIO BSC1010 taught by Professor Gwenhauner during the Fall '10 term at Broward College.

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