create a punnett square crossing two individuals who are heterozygous for eyebrows.
Identify the genotypes( ratios)
Identify the phenotype (ratio)
Draw phenotype
To create a Punnett square for crossing two individuals who are heterozygous for eyebrows, we need to know the genotypes of the parents. Since both parents are heterozygous, we can represent their genotypes as "Ee" (where 'E' stands for the dominant allele for eyebrows and 'e' for the recessive allele).
Now, let's set up the Punnett square:
| E | e |
---------------------
E | EE | Ee |
---------------------
e | Ee | ee |
In this square, each column and each row represents one parent's possible allele combinations. The alleles from one parent are aligned vertically, while the alleles from the other parent are aligned horizontally.
Next, we can identify the genotypes and their ratios:
- The genotype EE represents individuals with homozygous dominant eyebrows.
- The genotype Ee represents individuals with heterozygous eyebrows.
- The genotype ee represents individuals with homozygous recessive eyebrows.
Looking at the Punnett square, we can see that there is one EE genotype (homozygous dominant), two Ee genotypes (heterozygous), and one ee genotype (homozygous recessive).
Therefore, the genotypic ratios are:
- EE: 1 out of 4 (1/4 or 25%)
- Ee: 2 out of 4 (2/4 or 50%)
- ee: 1 out of 4 (1/4 or 25%)
Now, let's identify the phenotypes and their ratios based on the genotypes:
- Individuals with the EE genotype will have the dominant phenotype for eyebrows.
- Individuals with the Ee genotype will also have the dominant phenotype for eyebrows.
- Only individuals with the ee genotype will have the recessive phenotype for eyebrows.
Since the genotypic ratio is 1:2:1 for EE:Ee:ee, the phenotypic ratio will be the same.
Therefore, the phenotypic ratios are:
- Dominant phenotype: 3 out of 4 (3/4 or 75%)
- Recessive phenotype: 1 out of 4 (1/4 or 25%)
Unfortunately, as an AI, I cannot draw the phenotype directly. However, based on the provided information, the phenotype would be individuals with dominant eyebrows (represented by the 'E' allele) in a higher ratio compared to individuals with recessive eyebrows (represented by the 'e' allele) in the offspring.