pedigree

The pedigree below tracks the presence of attached earlobes through a family's generation. Having attached earlobes is an autosomal recessive trait.

What is the genotype of individual I-1?

• X^eY

• ee

• EE

• Ee

• X^EY

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

The pedigree below tracks the presence of dimples through a family's generation. Having dimples is an autosomal dominant trait.

If individuals II-1 and II-2 have a fourth child, what is the probability that the child will have dimples?

• 25%

• 50%

• 75%

• 100%

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

The pedigree tracks Duchenne Muscular Dystrophy (DMD) through several generations. DMD is an X-linked recessive trait.

If individuals I-1 and I-2 had another son, what is the chance that he would have DMD?

• 0%

• 25%

• 50%

• 100%

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

A boy is born with an extra finger on one hand. Extra digits are known to be common in members of the father's (and the father has 6 fingers as well) extended family, but not the mother's. The boy's two sisters have normal fingers. What is the most likely explanation?

• X-linked inheritance, since only males are affected.

• Y-linked inheritance: Males inherit from their fathers.

• The extra finger trait is autosomal dominant.

• A spontaneous mutation occurred.

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

Explain the inheritance of this rare trait in the pedigree.

• The trait is X-linked recessive, inherited through the mothers.

• The trait is autosomal recessive.

• X-linked recessive.

• The trait is autosomal dominant.

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

Explain the inheritance of this rare disease in the pedigree.

• autosomal recessive

• The trait is X-linked dominant.

• The disease is inherited on the mitochondrial DNA.

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2