The problem describes a pedigree chart related to albinism, a recessive trait in humans. We are asked to: - Fill out the genotypes (AA, Aa, or aa) of each individual in the pedigree. - Determine the number of children the original couple had. - Determine the number of grandchildren they have. - Determine the sexes of the children. - Highlight the individuals that are carriers of albinism.

1. Problem Description

The problem describes a pedigree chart related to albinism, a recessive trait in humans. We are asked to:

- Fill out the genotypes (AA, Aa, or aa) of each individual in the pedigree.

- Determine the number of children the original couple had.

- Determine the number of grandchildren they have.

- Determine the sexes of the children.

- Highlight the individuals that are carriers of albinism.

2. Solution Steps

Step 1: Determine the genotypes of individuals with albinism.

Since albinism is a recessive trait, individuals with albinism must have the genotype $aa$. Based on the pedigree, we can identify the affected individuals (filled symbols) and assign them the genotype $aa$.

Step 2: Determine the genotypes of the parents of individuals with albinism.

If an individual has albinism ($aa$), they must have inherited one 'a' allele from each parent. This means that the parents must have at least one 'a' allele. Since they are not affected by albinism, they must also have at least one 'A' allele. Therefore, the parents of affected individuals must have the genotype $Aa$.

Step 3: Determine the genotype of the original couple.

The first generation consists of a male and a female. They have an affected daughter. Therefore, both parents must be carriers. So the genotypes of original couple would be $Aa$.

Step 4: Analyze the second generation.

The individuals in the second generation are a daughter with albinism ($aa$) and two unaffected children. We know their parents are $Aa$ and we also know one of them must be $Aa$ (daughter). The affected daughter must be $aa$. The other two children do not express the trait and so at least have one $A$ allele.

Step 5: Analyze the third generation.

The parents of the affected male are $Aa$ and they also have one female child without albinism. So she has at least one $A$ allele.

Step 6: Fill out the pedigree chart with genotypes.

- Original couple: Both $Aa$

- Daughter in the second generation: $aa$

- Other two children in the second generation: $Aa$

- Male in the third generation: $aa$

- Female in the third generation: $Aa$

Step 7: Count the number of children of the original couple.

The original couple has three children.

Step 8: Count the number of grandchildren of the original couple.

The original couple has two grandchildren.

Step 9: Determine the sexes of the children.

The original couple has one daughter and two sons.

Step 10: Identify the carriers of albinism.

The carriers of albinism are individuals with the genotype $Aa$. Based on our analysis, all unaffected individuals who are related to affected individuals and who have parents/offspring who are affected are carriers.

3. Final Answer

Fill out the blanks of the pedigree (AA, Aa, or aa):

- First generation: Both $Aa$

- Second generation: $aa$, $Aa$, $Aa$

- Third generation: $aa$, $Aa$

How many children did the original couple have? 3

How many grandchildren do they have? 2

What are the sexes of the children? One daughter, two sons.

Highlight the individuals that are carriers of albinism:

- Both individuals in the first generation.

- Two individuals in the second generation who are unaffected by albinism.

- One individual in the third generation who are unaffected by albinism.