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 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.

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