DNA
Your Unique Fingerprint
DNA
DEOXYRIBONUCLEIC ACID
WHAT IS DNA?
• The material in the nucleus that contains all of the cell’s genetic
information.
• The nucleus contains the master set of instructions that determines
• what each cell will become,
• how it will function and
• how long it will live before being replaced.
YOUR DNA DETERMINES:
• If you will be a boy or a girl
• How many limbs you will have
• The colour of your eyes, hair, skin …
• What species we belong to
CHROMOSOMES
• Every cell in your body has a
nucleus
• Inside each nucleus you will have
46 chromosomes
• ½ of these came from your mom,
and ½ came from your dad (23
from each parent)
A CLOSER LOOK
• When we zoom into one
chromosome, we find a long
stranded molecule = DNA
• The DNA is extremely long
and looks like a twisted
ladder
DNA SAMPLING
• DNA samples can be taken from:
• Cheek, skin swaps
• Blood samples
• Hair fibres
UH OH!
• DNA is identical in all of your cells.
• BUT … sometimes, random changes can occur … MUTATIONS
• A mutation is a random change in a cell’s genetic information
• A mutation can change the way a cell performs its job
• Things that may cause a mutation: radiation, chemicals
(mercury, lead), environment
DNA SCREENING
• The process of testing individuals to determine whether they have the
gene(s) associated with certain disorders.
GENETIC DISORDERS
Some disorders that can be tested using DNA screening are:
1. Down Syndrome – tested using an amniocentesis which allows a lab
tech to create a karyotype (a map of chromosomes) to determine if
trisomy 21 (3 chromosomes at 21 instead of 2) occurs.
2. PKU – tested using a blood sample to look for the presence or absence of
certain proteins. This indicated whether a person’s genes are functioning
normally. PKU is when a person cannot digest a certain protein in food
and the build up can be tragic.
3. Huntington Disease – testing a person to see if they have the gene
that causes the disease. Huntington’s affects nerve cells and causes
death.
THE FUTURE…
Altering Genes
• Some scientists have been combining DNA from different
species to produce a genetically modified organism
(GMO) or transgenic organism.
Cloning
• The process of creating identical genetic copies of an
organism from genes, cells or entire organisms.