Transcript Patterns of Heredity - Bishop Ireton High School

Patterns of Heredity
Karyotype
Picture of chromosomes arranged in
homologous pairs.
 #1-22 called autosomes
 #23 called sex chromosomes

Pedigree-graphic representation of a
family’s genetic history
Simple Recessive Diseases
(little,little)
Tay Sachs-missing enzyme that
metabolizes fats. Fats accumulate in brain.
Fatal
 Cystic Fibrosis- excessive mucous
production in the lungs.”Drown” in own
fluid
 Phenylketonuria-(PKU)- body can’t
metabolize phenylalanine into tyrosine –
Phenylalanine accumulates. Monitor intake
amount.

Simple Dominant Traits
(Big,Big or Big,little)
Widows peak
 Free hanging ear lobes(attached)
 Huntington’ Disease- slow ,progressive
neurological disease that appears after age
35-become incapacitated. Loss of muscle
and motor control.

SEX DETERMINATION
pair #23- sex chromosomes
 xx= female
 xy= male

Sex Chromosome Disorders
X0- Turners Syndrome-female who is
sterile
 XXY- Klinfelter’s Syndrome- males with
an extra X.Sterile.


No baby has been born without an X-vital
for embryonic survival. With no Y, baby is
female.Y chromosome contains sex
determining region that causes male
sexual development.
Nondisjunction
chromosomes fail to separate during
meiosis.
Ex. Down’s Syndrome- trisomy 21
extra #21 chromosome

Sex linked traits
Carried on the X chromosome
 Mostly males affected because they have
only 1 X chromosome
 Colorblindness
 Hemophilia-no clotting factor

XHXh- Female carrier
 XhY- Male affected
 XhXh- Female affected

Complex Inheritance Traits
Sickle cell anemia common to black African Americans
 Hemoglobin doesn’t bind to O2 properly
 Cells are sickle shaped
 Clot easily
 Homozygous(ss) have disease
 Heterozygous(Ss) show some traits

Blood groups
4 blood types-A, B, AB, O
 3 alleles- IA,IB,i


Type O is universal donor-no marker on
cell(generic)

Type AB- universal recipient- no
antibodies in serum
TYPE
GENOTYPE
On cells
In serum
A
IAIA/IAi
A
B
IBIB/IBi
B
AB
IAIB
A and B
Anti B
antibodies
Anti A
antibodies
Nothing
O
ii
Nothing
Anti A
antibodies
Anti B
antibodies