Transcript Ch. 10.5: Sex-Linked Traits

Ch. 10.5: Sex-Linked Traits
Genes located on the X or Y chromosome
XX = Female; XY = Male
Objectives:
1. Explain how sex-linked genes
produce different inheritance
patterns in males and females.
2. Explain why most sex-linked
disorders are more common in
males.
Vocab: sex-linked gene
X vs. Y
More genes on X
Male karyotype
Female karyotype
X: more than just genes
for sex traits.
Thomas Hunt Morgan & Fruit Flies
Discovers sex-linked traits.
Recessive white eyes more common in MALE fruit flies.
Females have to be homozygous recessive to have white eyes.
Males only need one recessive allele for trait.
Sex-linked genes affect MALES more than
females.
Females can be
carriers XNXn
Males will express
trait with just one
allele, XnY.
Females have to be homozygous recessive to express trait.
Sex-Linked Disorders
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Color-blindness
Hemophelia
Baldness
Fragile X
Versions of Muscular Dystrophy
These are recessive disorders.
• There are dominant disorders that are more prevalent in
females.
Color-blindness
Hemophelia
Prevents blood clots.
Without clotting
factors (proteins), you
can bleed to death.