Transcript Pedigree

Patterns of Heredity and Human
Genetics

Pedigree – made up
of a set of symbols
that identify males
and females, the
individuals affected
by a trait being
studied and family
relationships
(Family Tree)
Pedigree

Cystic Fibrosis (CF)
 Lethal genetic
disorder among
whites
 Thick mucus in
lungs and
digestive tract
 Defective protein
in the plasma
membrane

Tay Sachs Disease
 Missing enzymes
that breaks down
lipids
 Causes blindness,
progressive loss
of movement and
mental
deterioration

Phenylketonuria (PKU)
 Missing enzyme
needed to break
down amino acid
phenylalanine to a
different amino acid
tyrosine
 Damages central
nervous system
 Cannot break down
milk, results in
retardation

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Tongue Rolling
Hapsburg Lip - The lower lip and chin
protrude, sometimes forcing the mouth
open.
Earlobe (Free-hanging)
Hitchhiker’s Thumb
Thick Lips
Huntingtons Disease
Double Jointedness


Lethal, appears between ages 30 – 50
Breakdown of portions of the brain

Incomplete
Dominance
 Inheritance
pattern where the
phenotype of a
heterozygote is
intermediate
between those of
the 2
homozygotes

Ex.
 RR (Red
Flowers) x
R’R’ (white
flowers) = F1
offspring are
pink
R
R
R'
RR'
RR'
R'
RR'
RR'

With codominance, a cross
between organisms with two
different phenotypes produces
offspring with a third phenotype
in which both of the parental
traits appear together. .

All organisms have:
 Autosomes – non-sex
chromosomes that carry all
characteristics except sex
 Sex Chromosomes – two
chromosomes that determine sex
 XX – Female, X is rod shaped
 XY – Male, Y is J or hook shaped
Humans – 46 chromosomes
Autosomes – 44 chromosomes
Sex Chromosomes – 2 chromosomes
Drosophila – 8 chromosomes
Autosomes – 6 chromosomes
Sex Chromosomes – 2 chromosomes

Traits controlled by genes located on
sex chromosomes

Those carried on the X and Y chromosome
 1. Hemophilia – free bleeders (X chromosome)
 Person lacks the gene needed for clotting of
the blood
 2. Colorblindness – not being able to determine
the difference between colors, usually red and
green, usually found in males, caused by
recessive gene on X chromosome
Both conditions are recessive and appear most
often in males. A pedigree chart is used to trace
genetic traits in families