- Draw a 2 x 2 square.
- Name the alleles involved.
- Check the parents' genotypes.
- Label the rows with one parent's genotype.
- Label the columns with the other parent's genotype.
- Have each box inherit letters from its row and column.
- Interpret the Punnett square.
- Describe the phenotype.
Correspondingly, how do you find the percentage of a Punnett square?
Divide the number of boxes with a dominant allele byfourand multiply the result by 100 to get the percentchance thatan offspring will have the dominant trait. For example(2/4)*100 =50, so there is a 50 percent chance of anoffspring havingbrown eyes.
In this regard, how is Punnett Square used to determine the genotype?
The two things a Punnett square can tell youarethe genotypes and phenotypes of the offspring.Agenotype is the genetic makeup of the organism. Thisisshown by the three genetic conditions described earlier (BB,Bb,bb). The phenotype is the trait those genesexpress.
Types of Punnett Squares For a monohybrid cross, these are 2X2squareswith four boxes, each representing one fertilizationevent betweenthe parent gametes. The second type is used topredict theoutcome of breeding experiments where two traitsare beingfollowed and the Punnett square is larger, withsixteenboxes.