1. A Genetic Investigation
Exploring Albinism
A Genetic Investigation

2. Recall what you know about proteins…
Enzymes catalyze (speed up) chemical reactions.
Some enzymes are responsible for creating pigments, colored compounds like those found in the flowers of plants and in hair and eyes.

3. Alleles Involved in Albinism
The name of the pigment involved:
Allele for normal melanin production:
Allele for no melanin production:
Melanin A a

4. A a Genetic Cross What are the two possible eggs?
Mother’s genotype = Aa
Father’s genotype = Aa
What are the two possible eggs? A a

5. A a Genetic Cross What are the two possible sperm? A a
Mother’s genotype = Aa
Father’s genotype = Aa a
What are the two possible sperm? A a

6. A
Genetic Cross a AA Aa A Aa aa a

7. ¼ ½ ¼ 1:2:1 Ratio Genotypic Ratios What fraction are AA?

8. Give an example of two individuals who have the same phenotype, but different genotypes for the albinism gene. Explain how two individuals with the same phenotype can have different genotypes.

9. ¾ ¼ 3:1 Ratio Phenotypic Ratios What fraction are normal?
What fraction are albino?
3:1
Ratio

10. Will Sally and Emily’s babies look identical?