Transcript Genetic Disorders - Hicksville Public Schools / Homepage

LO: SWBAT explain the difference
between chromosome mutations and
gene mutations and give an example of
each.
DN: Quiz
HW: Review Book- Biochemistry (due
Monday)
Test Wednesday
Chromosome Mutation:
Causes a change
in chromosome
number.
Nondisjunction- occurs when homologous
chromosomes or sister chromatids fail to
separate during meiosis.
karyotype
Trisomy Vs Monosomy:
Trisomy 21
3 Copies of a
Chromosome
Down Syndrome
Monosomy X
1 copy of a
homologous pair
Turner Syndrome
What causes nondisjunction to
occur?
No one really knows
for sure, but the older
the age of the mother
the greater the
likelihood of having a
child with Down
Syndrome.
Trisomy 21
Chromosome Damage:
Part of a chromosome is
repeated.
Part of a chromosome is
missing.
Reversing a fragment of
them chromosome.
A fragment of one
chromosome attaches
to a nonhomlogous
chromosome.
Down Syndrome
extra copy of chromosome
• Trisomy 21- _______
21
• Problems with brain and eye development
• Problems with physical development
• Chance of having a baby with down
syndrome increases after the age of ____
35
Gene Mutations:
a change in the nucleotide
sequence of DNA.
cystic fibrosis
•
•
•
•
mutation in gene
in chromosome 7
Buildup of thick
_______ in
mucus
respiratory and
digestive tract
Defect in gene that
causes abnormally
large amounts of
mucus to build up
__________recessive must
have both copies
of the gene
Tay Sachs Disease
•
•
•
•
•
Mutation of gene on
chromosome 15
Absence of __________
enzyme
hexosaminidase A(hex-A)
Causes a ________
to
fat
accumulate in cellsespecially nerve cells
Usually death by age 5
recessive must have
_________both copies of the gene
•
•
•
•
sickle cell anemia
mutation of gene on chromosome 11
change in amino acid sequence of
hemoglobin
____________
crescent shaped
RBC’s are _________
recessive must have both copies of the
__________gene unable to transport ________
oxygen
throughout body
PKU
•
•
•
•
•
•
Mutation on gene of chromosome 12
enzyme to break down the
Missing _________
amino acid phenylalanine
phenylalanine accumulates in blood and
______________
tissue
Neurological problems, mental retardation
Treated with a well maintained diet- cannot
consume products with phenylalanine in ithigh ________
protein foods
__________recessive must have both copies of the
gene
Huntington’s disease
•
•
•
•
Dominant if you have the gene, you
__________have the disease
Neurological disorders
Chromosome 4
after child
Symptoms show up ______
bearing years
Huntington video
Huntington 2
What do these gene mutations
have in common?
They all affect the shape of proteins!! If we
change the shape of proteins (enzymes) they
will not function properly and this will affect
our phenotype.