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Who is smarter?
Chimp speakhttps://www.youtube.com/watch?v=NBFBbFcixRY
Chimp intelligence
https://www.youtube.com/watch?v=zsXP8qeFF6A
http://genetics.thetech.org/online-exhibits/what-color-eyeswill-your-children-have
DNA
What has DNA?
http://genetics.thetech.org/onlineexhibits/genes-common
Where is DNA found?
DNA is found inside the cell in the nucleus.
What is a chromosome?
A chromosome is a
structure in the nucleus
that contains the DNA. It
is how we keep our DNA
organized.
DNA is found in all our cells
Humans have 46 chromosomes
There are 23 pairs of chromosomes
23 X 2 = 46 Total
We have 46 chromosomes
There are 23 pairs of chromosomes
23 X 2 = 46 Total
How many are from mom?
23
How many are from dad?
23
The last pair of chromosomes
makes us male or female
XY
XX
DNA shaped building being
made in Taiwan
What does DNA look like?
• Called a double helix
(double twist), sometimes described
as a twisted ladder
http://geneti
cs.thetech.or
g/onlineexhibits/zoo
ming-dna
• Don’t try this at home: If uncoiled, the
DNA in all the cells in your body would
stretch 10 billion miles—from here to Pluto
and back.
• One single strand is about 2 meters long!!!
Discovery of the structure of DNA
This model of DNA was
described by James Watson and
Francis Crick in 1953 (with the
help of many others) and is
therefore called the Watson-Crick
Model of DNA. (they won a
Nobel prize for this.
Remember, Rosalind Franklin also
played a big role! And Maurice
Wilkins !
DNA is made of smaller building
blocks
• These building blocks are
called Nucleotides.
If DNA was a necklace, the
nucleotides would be the
beads.
DNA is shaped like a ladder
• The nucleotides are on the inside
of the helix, like rungs of a
ladder.
• The outside of the helix is called
the backbone. This is like the
sides of a ladder.
DNA made of 4 types of
nucleotides (beads)
• They have different
types of bases
–
–
–
–
T
A
G
C
• The bases attach (bond)
to one another to keep
DNA a double helix
Two types of bond pairs:
A-T
G-C
Match the corresponding strand of DNA
with the correct base:
T---------A---------C---------C---------C---------A---------G---------C---------T---------T----------
Two types of bond pairs:
A-T
G-C
Match the corresponding strand of DNA
with the correct base:
T----------A
A----------T
C----------G
C----------G
C----------G
A----------T
G----------C
C----------G
T----------A
T----------A
Two types of bond pairs:
A-T
G-C
Mutation: A change in the DNA sequence. Can
cause disease or death.
T----------A
A----------G
C----------G
C----------G
C----------G
A----------T
G----------C
C----------G
T----------A
T----------A
Human Genome Project: (1960-2003) Scientists determined the
sequence (order) of all 6 billion bases (letters) in human DNA.
It is like having a manual to the human body.
• We have about 24,000 genes
• Has helped identify over 1800 diseases
• There are now over 2000 tests for genetic diseases
http://www.ncbi.nlm.nih.gov
Genetic Testing: medical test where our DNA is examined
to look for genes that can cause genetic disorders.
Reasons for testing:
• Finding genetic diseases in unborn babies
• Finding out if people carry a gene for a disease and might pass it on to their
children
• Screening embryos for disease
• Testing for genetic diseases in adults before they cause symptoms
• Making a diagnosis in a person who has disease symptoms
• Figuring out the type or dose of a medicine that is best for a certain person
Genetic testing:
https://www.youtube.com/watch?v=jiJrM3GX-Qg
(SMARTnotebook)
DO NOW: Arrange from largest to smallest:
Largest
DNA
Cell
Chromosome
Nucleotide
Nucleus
Smallest
Genetics Part II
Review:
We know DNA is a set of instructions (the
blueprint) found in the nucleus.
It is useless unless we use the instructions
to build things our cell needs!
Where do we find genes?
• Genes are specific sections on the
chromosome that contain instructions.
What are genes?
Genes are the special sections of the chromosome that
contain the code to make proteins.
Genes
Empt
y
Space
There are unimportant spaces between genes that don’t make
anything!
GeneProtein
• The instructions are the order of the nucleotides
(A,T,G,C). The letters are a code that the cell can
read to figure out what to make.
ACGTGCGATTTCAGCT
Hemoglobin
(carries oxygen in blood)
TCGCCAAATCGAATC
Keratin
(in hair & nails)
GeneProtein
• Every one gene contains the instructions to
build one protein.
Our 46 chromosomes contain thousands of genes that are
used to make thousands of different proteins!
Protein Review:
• They are made up of smaller building
blocks called amino acids.
• Used to make hormones and enzymes.
• Proteins can also be used to build and repair
body parts.
• We get protein in our diet from meats,
beans, fish, nuts, etc.
How exactly are the instructions
used?
• The order of the nucleotides (A,T,G,C) tells the
cell what amino acids to string together to make
the protein.
• There are 20 different amino acids that are used
to make the different proteins in our body.
After proteins are made, they are folded into different
shapes, and this allows them to do different things.
Hemoglobin – folds into a nest that
allows oxygen to sit in the middle.
Keratin – folds into fibers to
leep hair & nails strong
Structure  Function
How a protein is built (its shape and structure)
determines what jobs it can do for the cell (its
function).
Example: Zipper
Structure:
Function:
What organelle makes proteins?
The ribosome
(the little dots in the cell)
Why do we look like our parents?
• 23 chromosomes from mom, 23 chromosomes from
dad
• Chromosomes contain genes which code for proteins
• We are making a combination of proteins that our
mom & dad have!
– for hair and eye color
– for height and weight
– that make dimples, freckles, etc.
What makes our cells different?
All our cells contain a
nucleus with the same DNA
(46 chromosomes, 23 from
mom and 23 from dad).
What makes our cells different?
Only certain instructions
(genes) are used in each cell!
Blood cells- use the genes
with the instructions needed
to make hemoglobin to carry
oxygen in our blood
Nerve cells- use the genes
needed to make proteins that
transfer information in our
nervous system
Heart cells- use genes that
create proteins to make our
heart beat
Gene control
Turned on genes= they
make proteins
We can control genes by
turning them on or off.
Different
genes
are
switched
“on”
in
our
different cells.
Keratin- makes hair into
strong, long strands
Keratin
Melanin
Melanin- Gives our hair
color. (the more you
have, the darker your
hair will be!)
Gene control Is called Gene Expression
If a gene is turned on it is being “expressed.”
The genes are showing themselves, just like we
do when we express ourselves.
Expressed
Not Expressed
The Environment influences our Genes
• Childhood nutrition- affects adult height
• Temperature changes- effect coat color in Himalayan
rabbits
• Light intensity – chlorophyll production in plants.
Plants grown in low light are pale
• Expression of cancer genes influenced by lifestyle
choices – smoking, drinking.
Bad effects of the environment
The environment can
mutate (change) our
DNA.
–
–
–
–
X-rays
Nuclear Radiation
Solar radiation (the sun!)
Chemicals (toxins)
These mutations can cause Cancer! 
Cancer
• Mutations occur in important places in our
DNA(this breaks our genes) !
– Bad genes = cells cant control themselves
• Cancer cells keep reproducing, and form a tumor
Tumor= ball of cells
• The tumor cells steal nutrients from the healthy
cells, and it takes up important space. If it is
cancerous, it can spread & take over our body.
Benign tumor- Not
cancerous, doesn’t spread to
other parts of the body.
Malignant tumor (BAD!)cancerous, can spread to
other parts of body