Human hair is inherited by incomplete dominance. Human hair may be curly (CC) or straight (cc). The heterozygous genotype (Cc) produces wavy hair. Show a cross between two parents with wavy hair

The problem states that wavy hair is produced by the heterozygous genotype (Cc). Since both parents have wavy hair, their genotypes are both Cc.

Each parent (Cc) can produce two types of gametes: C and c.

From the Punnett square, the possible genotypes are:

• CC: 1 out of 4
• Cc: 2 out of 4
• cc: 1 out of 4 The genotypic ratio is $1 \text{ CC} : 2 \text{ Cc} : 1 \text{ cc}$.

Based on the genotypes and the given information:

• CC produces curly hair.
• Cc produces wavy hair.
• cc produces straight hair. So, the phenotypes are:
• Curly hair (CC): 1 out of 4
• Wavy hair (Cc): 2 out of 4
• Straight hair (cc): 1 out of 4 The phenotypic ratio is $1 \text{ Curly} : 2 \text{ Wavy} : 1 \text{ Straight}$.

The cross between two parents with wavy hair (Cc x Cc) results in offspring with the following ratios:

• Genotypic Ratio: $\boxed{1 \text{ CC} : 2 \text{ Cc} : 1 \text{ cc}}$
• Phenotypic Ratio: $\boxed{1 \text{ Curly} : 2 \text{ Wavy} : 1 \text{ Straight}}$