Transcript Advances in Genetics - Conackamack Middle School

Advances in Genetics
Pages 132-138
What are the methods used
to make new organisms?
1. Selective
breeding
a. Inbreeding
b. hybridization
2. Cloning
3. Genetic
engineering
A “puggle” is part pug and part
beagle. This is an example of
selective breeding called
hybridization.
What is selective breeding?
• Selecting the best organisms to be
parents of the next generation.
• Why selectively breed plants or
animals?
– Increases the value of the species as a
whole.
• What’s an ex. of selective breeding?
– Cows that produce the best milk are bred
together to make even better offspring.
Inbreeding
• Crossing two parents that have very similar sets
of alleles.
• What do the offspring look like?
– VERY similar to their parents.
• What’s a goal of inbreeding?
– Getting the exact trait you want
– Ex. German Shepards.
• What’s the bad side of inbreeding?
– Increases the chances of passing on genetic
disorders.
Pandas often suffer from infertility and high infant
death rates due to inbreeding. Often isolated from
finding other mates, the Pandas will mate by inbreeding
Hybridization
• What is hybridization?
– Crossing two genetically different
animals
Cloning
• Name one downfall to selective breeding.
– You can’t control exactly what gets passed on.
• What method can you do instead that will
make sure you get the exact traits you want?
– Cloning
• What is a clone?
– Organism that is genetically identical to the
organism from which it was produced.
• What is a clone’s DNA like?
– Same genes as whatever organism
it was produced from.
What can be cloned?
• Plants, animals, bacteria can be
cloned
• How do you clone a plant?
– Cutting a small piece of the plant
and planting it so that it can grow
full size
• How do you clone an animal?
– Nuclear transfer
• What is an example of this
process?
– Dolly the sheep was the first
mammal ever produced by nuclear
transfer.
Dolly died young at
the age of 6 from a
lung disease.
However she was
able to birth 4
lambs of her own
during her lifetime.
Let’s clone a mouse…
• http://learn.gene
tics.utah.edu/uni
ts/cloning/clicka
ndclone/
Genetic Engineering
• What is Genetic Engineering?
– Genes from one organism are moved into
the DNA of another.
• What happens during “gene splicing?”
– DNA is cut open and a part of another DNA
is inserted in.
• Why do this?
– Helps in making medicines, improving food
and tries to cure human genetic disorders.
Using
Bacteria
to make
Insulin
• What are other exs. of genetic
engineering helping humans?
– Human growth hormone can be made.
• How else is genetic engineering
beneficial?
– Can be used to make plants and animals that
can survive longer and more efficiently.
• How is genetic engineering used in
animals?
– Clotting factor gene is inserted into cow’s
DNA. The factor can now be extracted
from the milk and given to patients.
What is gene
therapy?
• Inserting working copies of a gene directly
into the cells of a person with a genetic
disorder.
• Name an example of gene therapy at work.
– Copies of the DNA sequence of a protein that
Cystic fibrosis patients need is inserted into a
virus and then put in their breathing treatments.
The hope is that the virus will multiply in the lungs
and the protein will get passed on to the patients.
• What’s unique about DNA?
– No two people (except for
twins) have the same DNA.
– You can get someone’s DNA
from their skin, hair, blood,
body fluids, etc….
• What is DNA
fingerprinting?
– http://www.pbs.org/wgbh/n
ova/sheppard/analyze.html
Human Genome
•
Project
What is a genome?
– All the DNA in one cell
of an organism.
• What has the Human
Genome Project
accomplished so far?
– First draft complete in
2003 (took 13 years!)
– Cost almost $3 billion
to complete.
– Recognized about
30,000 genes
– Each gene is about
3000 bases long