Biotechnology and the
Human Genome Project
allowing only those
animals with desired characteristics to
produce the next generation
Humans use selective breeding with
plants, animals and other organisms.
individuals to bring together the best of
Inbreeding is the continued breeding of
individuals with similar characteristics.
Inbreeding does have risks, such as recessive
alleles for genetic defects. (blindness/joint
deformities in German shepherds and golden
Breeders can increase the genetic variation in a
population by inducing mutations, which are the
ultimate source of genetic variability.
Scientists use their knowledge of the structure of
DNA and its chemical properties to study and
change DNA molecules.
Genetic engineering is making changes in the
DNA code of a living organism.
cuts DNA molecules into
smaller fragments; each enzyme will only fit one
a mixture of DNA fragments
is placed at one end of a porous gel, and an
electric voltage is applied. It separates
fragments by size.
Short sequences can be assembled in
laboratories. “Synthetic” sequences can be
spliced with “natural” sequences. These new
strands are called recombinant DNA.
Polymerase Chain Reaction (PCR)
many copies of a gene
During transformation, a cell takes in DNA from
outside the cell. This external DNA becomes a
component of the cell’s DNA.
a small, circular DNA molecule
a gene that makes it
possible to distinguish bacteria that carry
the plasmid from the ones that don’t.
If transformation is successful, the
recombinant DNA is integrated into one of
the chromosomes of the cell.
constructing organisms that contain
genes from other species.
Genetic engineering has spurred the growth of
Transgenic animals are made with growth
hormones, immune systems, etc.
Transgenic plants produce natural insecticides,
resistance to weed
killing chemicals, etc.
Cloning is making exact DNA replicas, then
making copies of the animal or plant itself.
Human Genome Project
There are now tests that make it possible to
detect many genetic disorders.
DNA fingerprinting analyzes sections of DNA
that have little or no known function but vary
widely from one individual to another. (CSI)
The Human Genome Project is an ongoing effort
to analyze the human DNA sequence.
In gene therapy, an absent or faulty gene is
replaced by a normal, working gene.
What are some ethical issues in Human