1. Pedigrees

2. Using Pedigrees
Humans cannot be selectively bred like Mendel’s pea plants
pedigree – traces the occurrence of a trait through generations of a family.
Geneticists use pedigrees to:
Study human genetic disorders.
Predict the probability that a person has or carries a specific trait.

3. Using Pedigrees
Pedigrees are also useful for tracing a class of inherited traits called sex-linked disorders.
sex-linked disorders – a trait linked with an allele on a sex chromosome.
X linked – on the X chromosome
Y linked – on the Y chromosome

4. Write these in your notes!
Pedigree Symbols
male
Write these in your notes!
female
mating (square on left)
children (birth order left to right)

5. Write these in your notes!
Pedigree Symbols
Write these in your notes!
non-affected (does not have trait)
carrier (has a recessive gene for the trait)
affected (has the trait)

6. Pedigree Symbols I II III
Each generation is labeled with a roman numeral
Individuals are labeled from left to right starting with 1 I II
III 1 2 3 5 6 7 4 9 8 10 11 12 13 14

7. Typical Pedigree Types
autosomal dominant
autosomal recessive
sex linked dominant
sex linked recessive

8. Autosomal Dominant homozygous
Inheritance pattern with one parent affected and ALL of the offspring are affected.
will usually have at least one affected in each generation
Homozygous for the trait

9. Autosomal Dominant heterozygous
Inheritance pattern with one parent affected and half of the offspring are affected.
will usually have at least one affected in each generation
Heterozygous for the trait

10. Autosomal Recessive
Inheritance pattern in which both parents appear to be non-affected but can produce affected children.
Affected children are homozygous recessive
Parents can be shown two ways

11. X Linked Dominant
Inheritance pattern in which there is a dominant trait carried on the X chromosome.
Affected father – all daughters affected, no sons
Affected mother sons or daughters can be affected

12. X Linked Recessive
Inheritance pattern in which there is a recessive trait carried on the X chromosome.
His daughters can be carriers for the trait
Only the sons express the trait, unless the daughter is homozygous
Carrier mother
Affected father

14. Russian Royal Families
Prince Albert
Queen Victoria

15. Russian Royal Families
Instead of numbering them traditionally, start at the top left with #1 and work your way across and then down
Number all of the individuals in the pedigree chart.

16. Russian Royal Families
Prince Albert________
Queen Victoria______ 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 23 22 24 25 26 27 28 29 30 44 45 46 41 42 43 38 39 40 34 35 36 37 32 33 31

17. Which numbers are the children of 7 and 8?
Prince Albert________
Queen Victoria______ 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 23 22 24 25 26 27 28 29 30 44 45 46 41 42 43 38 39 40 34 35 36 37 32 33 31

18. Color all hemophilia carriers blue
Prince Albert________
Queen Victoria______ 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 23 22 24 25 26 27 28 29 30 44 45 46 41 42 43 38 39 40 34 35 36 37 32 33 31
What do all the carriers have in common?

19. Color all hemophiliacs red
Prince Albert________
Queen Victoria______ 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 23 22 24 25 26 27 28 29 30 44 45 46 41 42 43 38 39 40 34 35 36 37 32 33 31
What do the affected have in common?

20. What relation is number 22 to Queen Victoria?
Prince Albert________
Queen Victoria______ 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 23 22 24 25 26 27 28 29 30 44 45 46 41 42 43 38 39 40 34 35 36 37 32 33 31
Do you think Alexis has hemophilia?

21. Color all non-affected individuals yellow
Prince Albert________
Queen Victoria______ 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 23 22 24 25 26 27 28 29 30 44 45 46 41 42 43 38 39 40 34 35 36 37 32 33 31

22. Complete the assignment by circling the right answer choice then label individuals mentioned in the story.
Turn in to the tray when finished