12. Complete the following monohybrid cross.

Two parents that are heterozygous for brown eyes. Be sure to identify the genotypes of the parents, complete the Punnett square, identify the phenotypes with genotypes and the ratio of the phenotypes.

What percent of the offspring have blue eyes?

My answer: 25% of the offspring would have blue eyes if the parents are heterozygous.
My question: Did I answer the questions fully, if not can you explain what to add.

The ratio of genotypes? 3:1 ?

did you draw the Punnett square?

Your answer is partially correct, but there are a few more details you can add to fully answer the question.

To answer the question fully, you should first identify the genotypes of the parents. You mentioned that they are heterozygous for brown eyes, but you didn't specify what genetic symbol or letter represents the brown eye allele. Let's assume that the dominant allele for brown eyes is represented by B, and the recessive allele for blue eyes is represented by b.

Therefore, the genotypes of the parents would be:

Parent 1: Bb (heterozygous for brown eyes)
Parent 2: Bb (heterozygous for brown eyes)

To complete the Punnett square, you would cross the alleles of the parents:

| B | b
------------------------------
B | BB | Bb
------------------------------
b | Bb | bb

Now, to determine the phenotypes and genotypes of the offspring, you can read the combinations of alleles in the Punnett square. The possible genotypes of the offspring are BB, Bb, Bb, and bb.

BB: Homozygous dominant for brown eyes
Bb: Heterozygous for brown eyes
Bb: Heterozygous for brown eyes
bb: Homozygous recessive for blue eyes

So, the phenotypes with their corresponding genotypes are:

Brown eyes (BB or Bb): 75% of the offspring
Blue eyes (bb): 25% of the offspring

Therefore, 25% of the offspring would have blue eyes.

To summarize:

- Parents' genotypes: Bb x Bb
- Phenotypes:
- Brown eyes (BB or Bb): 75%
- Blue eyes (bb): 25%

Your answer is partially correct, but it seems to be missing some information. To answer the question fully, let's go through the steps to complete the monohybrid cross and determine the likelihood of offspring having blue eyes.

Step 1: Identify the genotypes of the parents
The parents are heterozygous for brown eyes. Let's represent the brown eye allele as B and the blue eye allele as b.

The genotypes of the parents can be represented as:
Parent 1: Bb
Parent 2: Bb

Step 2: Create a Punnett square
A Punnett square is a grid that helps visualize the possible combinations of alleles the offspring can inherit. Each row and column represents the alleles from one parent.

Based on the genotypes of the parents, the Punnett square for this monohybrid cross would look like this:

| B | b |
-----------------------------
B | BB | Bb |
-----------------------------
b | Bb | bb |

Step 3: Determine the genotypes and phenotypes of the offspring
From the Punnett square, we can see the possible genotypes of the offspring. The combinations are:
- 1 BB genotype (brown eyes)
- 2 Bb genotypes (brown eyes)
- 1 bb genotype (blue eyes)

Step 4: Calculate the probability of offspring having blue eyes
Out of the four possible genotypes, only one has the bb combination, which corresponds to blue eyes. Therefore, there is a 1 in 4 (or 25%) chance that an offspring will have blue eyes.

So, to answer the question completely, you could say:
"The parents in this monohybrid cross are heterozygous for brown eyes, with genotypes Bb. The Punnett square shows that the possible genotypes of the offspring are BB (brown eyes), Bb (brown eyes), and bb (blue eyes). Therefore, the ratio of offspring with blue eyes would be 1 out of 4, or 25%."