Suppose a species of tulip has three alleles for the gene that codes for flower color. The C R allele produces red tulips, the C p allele produces purple tulips, and the C w allele produces white tulips. C R is dominant over C p and C w, and C p is dominant over C w. For each cross, determine the expected phenotype ratio of offspring flower color.

Answer and Explanation:

Available dа ta:

The Cr allele produces red tulips The Cp allele produces purple tulips The Cw allele produces white tulips. Cr is dominant over Cp and Cw Cp is dominant over Cw

Cross 1

Parental) CrCp x CpCw

Gametes) Cr Cp Cp Cw

Punnet Square) Cr Cp

Cp CrCp CpCp

Cw CrCw CpCw

F1 phenotype ratio)

2/4=1/2 Red flowers, CrCp and CrCw

2/4=1/2 Purple flowers, CpCp and CpCw

Cross 2

Parental) CrCw x CpCw

Gametes) Cr Cw Cp Cw

Punnet Square) Cr Cw

Cp CrCp CpCw

Cw CrCw CwCw

F1 phenotype ratio)

2/4=1/2 Red flowers, CrCp and CrCw

1/4 Purple flowers, CpCw

1/4 White flowers, CwCw

Answer: The expected phenotype ratio of cross between CR and Cp is 1:1:2.

1 for CC,

1 for Cp, purple

2 for CR and Rp (red) all which are offsprings from the cross.

For cross between Cp and Cw, phenotype ratio is 1:1:2.

1 for CC,

1 for Cw, white,

2 for Cp and pw, purple.

Explanation:

Phenotype gives the observable characters of an individual.

Here, the character observed is flower color of tulip species.

The expected phenotype ratio of cross between CR and Cp is 1:1:2. The offsprings from the cross are CC, Cp, CR and Rp

1 for CC,

1 for Cp, purple

2 for CR and Rp red, since red is dominant over purple.

For cross between Cp and Cw, phenotype ratio is 1:1:2. The offsprings from the cross give CC, Cw, Cp and pw

1 for CC,

1 for Cw, white,

2 for Cp and pw, purple since purple is dominant over white.