Real exceptions - (a common autosomal recessive disease)...

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Real exceptions mitochondrial inheritance The human mitochondrion has a small circular genome of 16,569 bp which is remarkably crowded. It is inherited only through the egg, sperm mitochondria never contribute to the zygote population of mitochondria. There are relatively few human genetic diseases caused by mitochondrial mutations but, because of their maternal transmission, they have a very distinctive pattern of inheritance. A mitochondrial inheritance pedigree All the children of an affected female but none of the children of an affected male will inherit the disease. uniparental disomy Although it is not possible to make a viable human embryo with two complete haploid sets of chromosomes from the same sex parent it is sometimes possible that both copies of a single chromosome may be inherited from the same parent (along with no copies of the corresponding chromosome from the other parent.) Rare cases of cystic fibrosis
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Unformatted text preview: (a common autosomal recessive disease) have occurred in which one parent was a heterozygous carrier of the disease but the second parent had two wild type alleles. The child had received two copies of the mutant chromosome 7 from the carrier parent and no chromosome 7 from the unaffected parent. linkage When two genes are close together on the same chromosome they tend to be inherited together because of the mechanics of chromosome segregation at meiosis. This means that they do not obey the law of independent assortment. The further apart the genes are the more opportunity there will be for a chiasma to occur between them. When they get so far apart that there is always a chiasma between them then they are inherited independently. The frequency with which the genes are separated at miosis can be measured and is the basis for the construction of genetic linkage maps (of which, more in lectures 8 & 9 )....
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This note was uploaded on 11/22/2011 for the course CHEMISTRY CHM1025 taught by Professor Laurachoudry during the Fall '10 term at Broward College.

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