Genotypic Ratios and Phenotypic Ratios for Punnett Squares

In this video I will discuss setting up the ratios and percents of a punnett square.
Once you have set up the Punnett square you can begin writing out the genotype ratios and the phenotype ratios
When writing the ratios use, homozygous dominant heterozygous, homozygous recessive.

You can write the genotype ratios and the phenotype ratios

Remember when calculating percents each box equals 25%

Example 1

Tall is dominant to short
Both parents are heterozygous

We will first set up the ratios
We will set them up
Homozygous Dominant Heterozygous Homozygous recessive

Genotype will be
1:2:1
The percents will be
25:50:25


Phenotype will be
3:1 remember a capital letter will be dominant and you only get a recessive trait when having two lower case letters

Example two red color is dominant to white

You have a heterozygous parent and a homozygous for the dominant trait

Genotype will be

0 for homozygous dominant
2 heterozygous
2 homozygous recessive
Written
0:2:2 or a 2:2 or reduce to 1:1
Genes vs Alleles
   • Alleles vs Genes  | Genetics |