Probability of II-1 Homozygous Normal in Albinism Pedigree

Introduction:
Albinism is an autosomal recessive disorder that affects the production of melanin in the skin, hair, and eyes. It is caused by mutations in genes that are involved in the production of melanin. In this pedigree, we will determine the probability of II-1 being homozygous normal for the albinism gene.

Pedigree:
The pedigree shows the inheritance of albinism in a family. The affected individuals are shaded while the unaffected individuals are unshaded. The parents of the affected individuals are heterozygous carriers.

Explanation:
To determine the probability of II-1 being homozygous normal, we need to first determine the genotype of II-2 and I-2. II-2 is affected by albinism, which means that she is homozygous recessive (aa). I-2 is the parent of II-1 and is a heterozygous carrier (Aa). Therefore, we can construct a Punnett square to determine the probability of II-1 being homozygous normal.

| | A | a |
|---|-------|-------|
| A | AA | Aa |
| a | Aa | aa |

From the Punnett square, we can see that there is a 50% chance of II-1 being heterozygous (Aa) and a 50% chance of II-1 being homozygous normal (AA). This is because I-2 can pass on either the dominant (A) or recessive (a) allele to II-1.

Conclusion:
The probability of II-1 being homozygous normal for the albinism gene is 50%. This means that there is an equal chance of II-1 being homozygous normal or heterozygous for the albinism gene.

Where is pedigree