If the mother and grandmother of a given family both exhibit a half dozen phenotypic effects of a mitochondrial disorder, how is it possible that the mother's three children each have different phenotypes from one another and different degrees of

severity?


Phenotypes are directly dependent on the number or percentage of mutated mitochondria per cell. Thus, cells that inherit more of the mitochondria with the mutation will show a more severe phenotype than those with enough normal mitochondria to maintain the wild-type function of the gene. If, during embryonic development, the cells that gave rise to a particular organ or tissue are derived from a cell with more of the mutant mitochondria, that individual will inherit the phenotype associated with that particular tissue defect. Similarly, if the cell that gave rise to a particular tissue or organ had mostly normal mitochondria, that individual may be phenotypically normal with regard to that tissue or organ.

Biology & Microbiology

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Sugars leave the source region and immediately enter into a ____, followed by direct movement into the ____

a. pit, perforation plate b. companion cell; sieve element c. pit, vessel element d. plasmodesmata, sink e. phloem tube, companion cell

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Which of the following is not a secondary

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Traits that have a continuous distribution are known as

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