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