In a family from Bohol, Tatay Ramon has dimples and is heterozygous (Dd) and Nanay Sisa has no dimples (dd). What are the parent genotypes and phenotypes, and what are the F1 genotypes, phenotypes, ratios, and percentages?

What the problem is asking

You are doing a simple monohybrid cross for one trait (dimples). The key is that $D$ is the dominant allele (dimples) and $d$ is the recessive allele (no dimples).

Parent generation (P): genotype and phenotype

• Tatay Ramon: genotype $Dd$, phenotype = has dimples (because $D$ is dominant)
• Nanay Sisa: genotype $dd$, phenotype = no dimples

Making the Punnett square for $Dd \times dd$

Gametes:

• Tatay Ramon ($Dd$) can make $D$ or $d$
• Nanay Sisa ($dd$) can make only $d$

Punnett outcomes:

• $D \times d \rightarrow Dd$
• $d \times d \rightarrow dd$

So the F1 offspring are split evenly between $Dd$ and $dd$.

F1 results (genotype, phenotype, ratios, percentages)

F1 Genotypes: $Dd$, $dd$

Genotypic ratio: $1 \, Dd: 1 \, dd$

Genotypic percentage:

• $Dd = 50\%$
• $dd = 50\%$

F1 Phenotypes: has dimples ($Dd$), no dimples ($dd$)

Phenotypic ratio: $1$ with dimples $: 1$ without dimples

Phenotypic percentage:

• With dimples = $50\%$
• Without dimples = $50\%$