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The Tools of Molecular Biology
How do scientists make changes to DNA?
*Scientists use their knowledge of the structure
of DNA and its chemical properties to study
and change DNA molecules.
*In genetic engineering, biologists make
changes in the DNA code of a living organism.
*DNA sequences can be changed in a
number of ways.
*Enzymes make it possible to take a gene from
one organism and attach it to the DNA of
another organism. Take DNA out,make
changes and put it back in.(Transformation)
*Such DNA molecules are sometimes called
recombinant DNA.
Genes from organisms as different as animals
& plants can be made to work in each other.
EX: Enzyme called luciferase(allows fireflies to glow) was
isolated & inserted into tobacco cells. RESULT: plants
glow in the dark
TRANSGENIC ORGANISMS
*GENETICALLY MODIFIED ORGANISMS THAT CONTAIN
GENES FROM OTHER SPECIES
KEY:Genetic engineering has spurred the growth of
biotechnology.
Transgenic Microorganisms
Transgenic bacteria produce important
substances useful for health and industry.
Transgenic bacteria have been used to produce:
insulin
growth hormone
clotting factor
Transgenic Plants
Transgenic plants are now an important part
of our food supply.
Many of these plants contain a gene that
produces a natural insecticide, so plants don’t
have to be sprayed with pesticides.
Transgenic Animals
Transgenic animals have been used to study
genes and to improve the food supply.
Mice have been produced with human genes
that make their immune systems act similarly
to those of humans. This allows scientists to
study the effects of diseases on the human
immune system.
Researchers are trying to produce transgenic
chickens that will be resistant to the bacterial
infections that can cause food poisoning.
Cloning
A clone is a member of a population of genetically
identical cells produced from a single cell.
In 1997, Ian Wilmut cloned a sheep called Dolly.
Dolly &Bonnie
CLONING DOLLY
FUTURE
Cloning may enable scientists to clone
organisms on endangered species list.
Humans
Scientifically possible but morally questionable