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Unit #3: Biotechnology
Splicing and Dicing:
DNA and Genetic Engineering
Topics Covered
• Basic genetics
– DNA, RNA
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Genetic Engineering
GMOs and Food Safety
Cloning
Fertility Treatments
Biotechnology
• The use of living organisms or systems to
develop products for a specific purpose
**The most dramatic and controversial
biotechnologies have been developed
since James Watson and Francis Crick
published the structure of DNA in 1953
Applications of Biotechnology
• Medicine
– Pharmaceuticals
• Pharmacogenomics
– Genetic testing
– Gene therapy
– Cloning
• Agriculture
– Crop yield
– Improved nutrition/taste
– Animal biotechnology
DNA: The Molecule of Life
• DNA stands for Deoxyribonucleic acid
– Stores information for structural and
functional components of living organisms
(proteins)
– Genetic information is passed
on from one generation to the next through sexual
reproduction
– All traits passed down from parent to offspring are
coded for by DNA
• In the nucleus of the cell, DNA is
stored in long strands called
CHROMOSOMES
-Composed of coiled DNA surrounding large
protein molecules called histones
• Information in DNA is stored on
chromosomes as GENES
– Each gene contains important information
– Instructions in genes code for different
characteristics: eye colour, height,
ear shape, length of a dog’s tail,
colour of a flower’s petals, etc…
Let’s take a look at
some traits that we get
based on the code of our
genes…
Earlobes:
Free ear lobes (dominant trait)
vs
Attached ear lobes (recessive trait)
• Free earlobes are those that
hang below the point of
attachment to the head.
• Attached ear lobes are attached
directly to the side of the head.
Widow’s peak: Widow’s peak (dominant trait)
vs
No widow’s peak (recessive trait)
Dimples:
Dimples (dominant trait)
vs
No dimples (recessive trait)
• Dimples are natural dents in
the face to the right or left of
the mouth. If a person has only
one dimple, they should be
counted as having dimples.
• Cleft chin is dominant over
no cleft.
Thumbs:
Straight thumb (dominant trait)
vs
Curved thumb (recessive trait)
• When viewed from the side,
curved thumbs can be seen
as part of a circle
Pinky:
Straight pinky (recessive trait)
vs
Bent pinky (dominant trait)
Mid-digit hair: Mid-digit hair (dominant trait)
vs
No mid-digit hair (recessive trait)
Longer 2nd Toe: Longer 2nd toe is dominant
vs
2nd toe shorter than big toe
Tongue-Rolling: Rolling up edges (dominant trait)
vs
Not rolling (recessive)
The Genetic Code
• DNA is a double stranded molecule, made of
a string of building blocks called:
Nitrogen
NUCLEOTIDES
bases are like
of a
– each nucleotide is made up of 3 parts: “rungs”
ladder
Sugarphosphates
are the
backbones
– Nucleotides bond together into a ladder shape called
a DOUBLE HELIX
– There are 4 different nitrogen bases:
Adenine (A)
Think about hair colour…
Thymine (T)
Cytosine (C)
Everyone has a gene for hair
colour, but it’s the order of the
Guanine (G)
A always binds to T
C always binds to G
4 base pairs in the gene that
determines whether you will
have brown hair or blond hair!
**It is the order of the 4 bases that
determines the genetic code!
There are MANY possibilities!
Cells use the genetic information in DNA to
produce proteins
Proteins give rise to inherited genetic
characteristics
The portion of the DNA molecule that
controls the production of a particular
protein is called a gene
**A single molecule of DNA contains many
genes