Download 3a Unit 7 Genetics notes part 3

Genetics notes part 3
Non-Mendelian genetics
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Sometimes alleles are not just dominant and recessive.
Incomplete dominance:
o
o Heterozygous phenotype is
o Ex: Snapdragons color
Codominance:
o
o Heterozygous phenotype is
o Ex: Horses coat color
.
Multiple Alleles:
o Genes that have more than
o Genotype is still only
gives one allele each.
o Ex:
o Blood type alleles:
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Polygenic traits:
o
o Ex.:
.
control a trait.
.
, each parent only
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Sex Determination:
o Chromosome pairs 1-22 
o 23rd pair 
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Determine
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Indicated by :
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Male 
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Female
.
.
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Sex linked traits:
o Genes that are located on the
.
o Many sex linked recessive traits are seen in
because the
much smaller than the X chromosome.
o Example: Red-green colorblindness:
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Type of disorder:
Example: Hemophilia:
o Type of disorder:
 Environmental influences on gene expression:
 Gene linkage:
 Gene map:
is