Question

Everyone in Smurfette’s family has light blue skin, which is the dominant trait for body color in her hometown of Smurf Valley. Her family brags that they are a "true bred" or "purebred" line. She recently married a nice boy who has light yellow skin, which is a recessive trait. Create a Punnett square to show the possibilities that would result if Smurfette and her new husband had children.

Answer 1

Answer:

All their descendants will be heterozygous for the skin color, Bb, expressing blue skin.

Explanation:

Available data:

• Smurfette has light blue skin
• Her family is a "true bred" or "purebred" line.
• She married a boy who has light yellow skin
• blue skin is the dominant trait expressed by the B allele
• yellow skin is a recessive trait, expressed by the b allele

Cross: Smurfette  x  Husband

Parentals)            BB     x     bb

Gametes)          B   B       b     b

Phenotypes) blue skin     yellow skin

Punnett square)

                       B        B

             b      Bb      Bb

             b      Bb      Bb

F1) 100% of the progeny will be heterozygous for the skin color, Bb

     100% of the progeny will be blue-skinned.

Note: Although the progeny is blue-skinned, they are not true-bred anymore.