Pedigrees

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.

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

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

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)

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

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

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

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

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

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

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

Russian Royal Families Prince Albert Queen Victoria

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.

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

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

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?

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?

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?

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

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