The Forces of Evolution

mutation, 

genetic drift

gene flow or migration

selection.

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#Id: 2049

#Unit 8. Inheritance Biology

X-Linked Recessive Trait

a. Usually more males than females are affected.

b. Affected sons are usually born to unaffected mothers; thus, the trait skips generations.

c. Approximately half of a carrier (heterozygous) mother’s sons are affected.

d. Never passed from father to son.

e. All daughters of affected fathers are carriers.

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#Id: 2050

#Unit 8. Inheritance Biology

X-Linked Dominant Trait

a. Both males and females are usually affected; often, more females than males are affected.

b. Does not skip generations. Affected sons must have an affected mother; affected daughters must have either an affected mother or an affected father.

c. Affected fathers pass the trait to all their daughters.

d. Affected mothers (if heterozygous) pass the trait to half of their sons and half of their daughters.

TLS Online TPP Program

#Id: 2051

#Unit 8. Inheritance Biology

Y-Linked Trait

a. Only males are affected.

b. Passed from father to all sons.

c. Does not skip generations.

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#Id: 2052

#Unit 8. Inheritance Biology

Cytoplasmic Inheritance

a. Present in males and females.

b. Usually inherited from one parent, typically the maternal parent.

c. Reciprocal crosses give different results.

d. Exhibit extensive phenotypic variation, even within a single family.

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#Id: 2053

#Unit 8. Inheritance Biology

Homoplasmy- All mutated mitochondria

Heteroplasmy- wild type + mutant mitochondria

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#Id: 2054

#Unit 8. Inheritance Biology

Leber hereditary optic neuropathy (LHON)- People who have this disorder experience rapid loss of vision in both eyes, which results from the death of cells in the optic nerve.