Mendelian genes have specific loci (positions) on chromosomes. Chromosomes undergo segregation and independent assortment
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Explain the wild type phentoype.
The phenotype for a character most commonly observed in natural populations.
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Explain mutant phenotypes in a population.
Traits that are alternatives to the wild type suggesting mutations in the alleles over time.
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Sex-linked gene
A gene located on either sex chromosome.
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Genes found of the X chromosome.
X-linked genes
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Give an example of an X-linked gene.
Color blindness, Duchenne muscular dystrophy, Hemophilia
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What is a Barr body?
The inactive X in each cell of a female condenses into a Barr body.
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X-linked recessive disorders are much more common in ______ than in _______.
males, females
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In mammalian females, one of the two X chromosomes in each cell is randomly ____________during embryonic development
inactivated
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Each chromosome has______________ or ___________ of genes (except the Y chromosome)
hundreds or thousands
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Genes located on the same chromosome that tend to be inherited together are called ____________________
Linked Genes
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Offspring with nonparental phenotypes (new combinations of traits) are called
recombinant types, or recombinants
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A______ frequency of recombination is observed for any two genes on different chromosomes
50%
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Genes that are far apart on the same chromosome can have a recombination frequency near ____
50%
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In ____________________, pairs of homologous chromosomes do not separate normally during meiosis As a result, one gamete receives two of the same type of chromosome, and another gamete receives no copy
nondisjunction
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_______________ results from the fertilization of gametes in which nondisjunction occurred. Offspring with this condition have an abnormal number of a particular chromosome