1. You and Your Genes
in 10 minutes

2. Genes and Genes are found in the nuclei of your cells.
You are the result of two things...
The environment
eg sun will make
skin darker
and
Genes
Genes are found in the nuclei of your cells.
They are instructionsfor making proteins.
They can make structural proteins - these build the body,
and enzymes which speed up chemical reactions in the body.

3. largest
Inside each cell is a nucleus.
Inside the nucleus are 46 chromosomes.
Each chromosome contains thousands of genes.
Chromosomes are made of a chemical called DNA.
smallest

4. You have 46 chromosomes.
There are 23 pairs of chromosomes.
The 23rd pair = the sex chromosomes.
23 of your chromosomes come from your mother.
23 of your chromosomes come from your father.
XX = female
XY = male
A gene found on the Y chromosome causes embryos to develop as male

5. So - chromosomes come in pairs, and you have 23 pairs of chromosomes.
Your genes also come in pairs.
Different versions of genes are known as alleles.
The gene for ear lobe attachment is shown here.
E = unattached.
e = attached.
Which allele is dominant?
Will this person have attached or unattached ear lobes?

6. genetic cross Father = Ee Mother = Ee unattached Earlobes
what percentage
of their offspring
are likely to have
attached earlobes?

7. Cystic Fibrosis and Huntington's Disease
Two genetic diseases that you need to know about...
Cystic Fibrosis
and
Huntington's Disease

8. Cystic Fibrosis faulty allele is recessive Respiritory System
individual with one recessive allele is a carrier
individual with two recessive alleles has cystic fibrosis
what is the chance of two carriers having a child with CF?
Ff x Ff
Cystic Fibrosis
Digestive system
Thick sticky mucus in pancreas prevents enzyme release.
Food not digested properly.
Respiritory System
Thick sticky mucus blocks passageways in the lungs.
Breathlessness and respiritory diseases.

9. faulty allele is dominant
individual with one dominant alleles has Huntington's Disease
Symptoms of HD=
loss of muscle control
forgetfulness
loss of understanding
Huntingdon’s Disease

10. Nearly there...

11. PRE-IMPLANTATION GENETIC DIAGNOSIS GENETIC TESTING
adults, fetuses or embryos
remove a cell
test for disease causing allele
adults may choose
not to have children
termination of
fetus with disease
fertilisation takes place in lab
remove a cell from
8 cell embryo
test for disease
causing allele
only implant embryo
without disease
What can science
do about
genetic disease?
GENE THERAPY
could be used to cure
genetic disease eg CF
make lots of copies of
normal allele
put alleles into virus
virus 'infects' bone marrow cells
genetically modified cells placed back inside body

12. CLONING could be used to treat human illness - 'theraputic cloning'
stem cells
unspecialised cells can become any
type of cell
genetically identical
differences caused by environment
some organisms clone themselves eg spider plants
CLONING

13. should we test fetuses for genetic disorders?
remember the issues...
should we test fetuses for genetic disorders?
are you worried about employers or insurance companies knowing your genetic information?
is it ethical to terminate a fetus?
is gene therapy playing God? would you think so if it could cure you of a terminal illness?
is cloning animals acceptable?
how about humans?
why? why not?