Genetic Engineering

Power to Predict

Power to Choose

Power to Manipulate

A Perfect Family?

Designer babies

Ethics Clip

Genetic Technologies

•
Genetic Testing

•
PGD
–

Preimplantation Genetic
Diagnosis

•
Cloning

•
DNA Databases/DNA Fingerprinting

•
“Savior” babies

•
“Designer” babies/ IVF

•
Genetically modified animals and plants

Ethical Questions

•
Should we use our powers?

•
For what purpose?

•
Should there be limitations?

•
What are the possible consequences?


-

Socially?



-

Economically?



-

Environmentally?

13
-
1 Changing the Living World

•
1. Selective Breeding
–

method of


improving a species by allowing

only those individual organisms with desired
characteristics to produce the


next generation

2.
Purpose
–

taking advantage of

naturally occurring genetic variation in
organisms to pass desired traits on

Selectively
bred


Hybridization/Inbreeding

•
Animals: horses, cats dogs, pigs, cows




•
Plants: potatoes, corn, tomatoes, oranges,
apples


Hybridization

5. Crossing dissimilar individuals to bring
together the best of both organisms.



6. Ex: Burbank combined the disease
resistance of one plant with the food
-
producing capacity of another
–
Russet
Burbank potato. He also hybridized the
Shasta Daisy

Hybridization
–

Interesting Facts

•
Today, somewhere around 99 percent of U.S.
corn is grown from hybrid seed.

•
Fungus resistance

•
Early maturity

•
Heat tolerance

Inbreeding

7. Breeding of individuals with similar
characteristics

8. Ex: Dog Breeding
–

Poodle, Golden Retriever







9. Risks of inbreeding
–

since most members of a
breed are genetically similar, there is a chance of
bringing together two recessive alleles
–

genetic
defect. Ex: blindness, joint deformities in
German shepherds and golden retrievers.


Inducing Mutations

•
10. Breeders might induce mutations to increase
genetic variation in a population that might
produce mutants with desirable characteristics
that aren’t found in the original population

•
Since the 1950s, over 2,000 crop varieties have
been developed by inducing mutations to
randomly alter genetic traits and then selecting
for improved types among the progeny.

Ex: Ruby Star red grapefruit

Inducing Mutations
–

How?

•
11. Mutations can be induced by using
radiation and chemicals

Bacteria
-

mutations

•
12. Bacteria are useful when producing
mutations because their small size enables
millions of organisms to be treated with
radiation or chemicals at the same time. This
increases the chances of producing a useful
mutant.

•
13: Ex: oil
-
digesting bacteria

Polyploidy Plants

•
14. Polyploidy Plants are produced by using drugs
that prevent chromosomal separation during
meiosis.




•
15.
Polyploidy Plants are desirable because they are
often stronger and larger

Manipulating DNA

•
Genetic Engineering
-

making changes in the
DNA code of a living organism

•
Biologists are now able to


rewrite an organism’s DNA

•
No longer limited by the

•
variation already in nature

Tools of Genetic Engineering

Perform the following tasks:

•
DNA Extraction

•
Cutting DNA

•

Separating DNA

•
Reading the Sequence

•
Making Copies

•
Recombination


DNA Extraction

•
DNA Extraction


Cells are opened and

the DNA is separated from

The other cell parts

Cutting DNA

•
Cutting DNA
–

restriction enzymes

•
DNA molecules are too large to be analyzed

•
Each restriction enzyme cuts DNA at a specific
sequence of nucleotides


Separating DNA

•
Gel electrophoresis

(Virtual Lab)

•
Mixture placed at one end of a porous gel

•
Electric voltage

•
DNA has (
-
) charge

•
Migrates to (+) end

•
Smaller DNA
–

faster

•
Compare genomes

•
Locate genes

Reading the Sequence

•
Reading the Sequence

•
Single strand of DNA with unknown sequence added to
test tube

•
DNA polymerase, A T C G

•
Makes one new DNA strand

•
Chemical dyes
–

tags

•
Gel electrophoresis

•
Order tells sequence of bases

•
Study of specific genes, compare genes w/other
organisms, learn functions of genes


Making Copies

•
PCR Polymerase Chain Reaction

•
PCR

Song

GTCA

•
Primers
–

a place for

DNA polymerase to start

•
DNA heated
–

strands separate

•
Cooled

•
Makes copies between primers

•
Copies also serve as templates

•
Millions of copies easily

Cutting and Pasting

•
Recombinant DNA
–

produced by combining DNA
from different sources

•
Cell Transformation

–

cell takes in DNA from outside
the cell. This external DNA becomes a component of
the cell’s DNA

•
Plasmid
–

small circular DNA molecule in some
bacteria