Pedigrees

1
Pedigrees

• Section 12-2

2
General Questions

• If my mother has Bigfoot Disease, what is the
  probability that my grandchildren will have it?
• Have can I determine this?
• Are there any genetic disorders I am carrying
  that will be passed down to my children?

3
Pedigree

• - a family record that shows how a trait is
  inherited over several generations.

Generation 1 2 3 4 5
Normal Carrier Displays Trait
4
Hint

• Start by finding the genotypes of the recessive
  individuals (if the disorder is expressed in
  recessive individuals)

5
Pedigree Example
AA normal Aa carrier aa diseased
A
B
Aa or AA
Aa
Aa or AA
C
Aa or AA
D
Aa or AA
6
Hints

• All genotypes are made from half the mothers
  genes and half the fathers gene.
• A recessive parent can only provide a recessive
  gene.

7
Quiz Sample
X-linked recessive disorder
XNXn
XnY
XNXn
XNXn
XNX-
XNX-
XNX-
XnY
XnY
Normal female XX Normal male XY Diseased male
Key
8
Section Review

• Answer section review question 1 on page 232.

9
Next Time

• Pedigree exercises
• Possible Quiz?
• Are you related to SpongeBob Squarepants?