Download Pedigree ppt

What does pedigree mean?
Pedigree: a diagram that traces one trait
through several generations of a family
Pedigree Video
*Only for those who can’t watch it
on Haiku*
= female
= male
Example #1
How many girls? ___
How many boys? ___
mom
daughter #1
dad
daughter #2
son
mom
dad
oldest
daughter #1
youngest
daughter #2
son
A horizontal line connecting two
shapes represents a cross/marriage.
mom
dad
Example #2
A
C
How many crosses/marriages?
B
D
E
F
G
A vertical line extending down from a
marriage/cross represents that the
couple has children.
mom
dad
Carrier
• When a person is half shaded it means they
are a carrier.
– =A male who is affected by trait
– = A female who is affected by a trait
• Carrier: A person that carries ONE copy of the
gene, but it is masked by the dominant trait.
(hybrid).
How do you show that a
person has the trait? Shading
( shaded = recessive )
RR
Rr
rr
mutation
**A pedigree chart follows one trait.
Pedigree Symbols
Symbol
Meaning
Normal Female
Normal Male
Affected Female
Affected Male
Carrier Female
Carrier Male
Marriage
Reproduced (Had
Offspring)
A
C
B
D
questions…
E
F
G
Example #3
A
C
How many couples
have children?
B
D
H
H
G
E
F
M
J
N
K
L
O
?
P
Q
R
S
T
Pedigree charts help to trace genetic traits
such as diseases. Most genetic diseases are a
recessive gene.
If you have 1 recessive, you are a carrier, but
you are not sick.
Aa
If you have 2 recessive genes, you are sick
with the disease. (you are “affected”)
aa
In order for a trait to be dominant it has to
show up in EVERY generation.
How do you show twins?
A
C
B
D
E
F
Rr
mom
RR
dad
R = tongue roller
r = non-roller
__ __
son
__ __
__ __
Daughter 1 Daughter 2
R
R
R
RR
RR
r
Rr
Rr