1. Variation and Inheritance
National 5 Biology
Key Area 5:
Variation and Inheritance
National 4 Biology
Key Area 4
Genetic Information

2. By the end of the lesson you will be able to …..
Use family trees to identify the genotype and phenotype of individuals

3. Keep it in the family
Families look alike

4. Family trees or pedigrees

5. Now used by geneticists to predict genotypes and phenotypes in a family.

6. The McLelland Family Tree (Red hair is recessive phenotype)
Male - red
Male – non-red
Mrs Skillen
Mr Skillen
(the original) Mrs McLelland
(the original) Mr McLelland
Female - red
Female – non-red
R - non red
r – red hair
Annoying Little Brother
Perfect Child
(ME!)
My hubby
Brother
Hollie

7. What is the genotype for R? What is the genotype for S?
The allele for free earlobes (E) is dominant to the allele for fixed earlobes (e)
What is the genotype for R?
What is the genotype for S? Ee ee

8. Hh HH/Hh The allele for red hair (h) is recessive to non-red (H)
Work out what genotype the dad must be.
What 2 possible genotypes will the sister have? Hh
HH/Hh