1. Year 10, Pathway C 2012

2.  Inheritance  IntermediateDominant/recessive Offspring can show a mixture of both characteristics Offspring will show one characteristic or the other. NOT a mixture of the two.

3.  Dominant/recessive inheritance - Offspring will show only one of the characteristics of the parents (eg: either brown or blue eyes, not a mixture)  This type of inheritance has one dominant allele (capital letter) and one recessive allele (lower case letter)

4. Capital indicates a dominant allele

5. Lowercase indicates a recessive allele

6. BB results in brown eyes

7. bb results in blue eyes

8. Bb results in brown eyes as B dominates b

9.  Parent genotype: BbBb  Parent phenotype: BrownBrown  Parent gametes: B b B b  Offspring:BB Bb Bb bb How many offspring have brown eyes? How many blue? What are the genotypes of the F1 generation for the dominant/recessive eye colour gene?

10.  Offspring:BB Bb Bb bb  Genotypic ratio: ratio of the different genotypes  Eg: ¼ BB: ½ Bb: ¼ bb  Phenotypic ratio: ratio of the physical appearance  Eg: ¾ Brown: ¼ Blue