Download Ch 13 Genetic Engineering

Genetic
Engineering
Chapter 13
Changing the Living World
• Selective breeding
– Breeding animals with
characteristics we
want to produce
offspring with those
• Plants – Potatoes or
flowers
• Animals – dogs or
farm animals
Changing the Living World
– Hybridization
• Cross different
individuals to get
offspring with favorable
traits
• The result is a hybrid –
an individual produced
from the crossing of
two different
organisms.
Changing the Living World
– Inbreeding
• Breed similar individuals over and over to get
offspring with favorable traits
Changing the Living World
• Increasing variation
– Inducing mutations
• Radiation
• Chemicals
– Produce mutants –
an individual showing
the mutation
Changing the Living World
– Producing new
bacteria
• Small size allows for
millions to be treated
– Oil eating bacteria
Changing the Living World
– Producing new plants
• Chemicals that prevent
chromosomal
separation
– Polypoidy
• Larger and stronger
plants
13-2 Manipulating DNA
• How can scientists
manipulate the code?
• Scientists use their
knowledge of the
structure of DNA
and its chemical
properties to study
and change DNA
13-2 Manipulating DNA
• Tools of Molecular
Biology
– Genetic Engineering
• Making changes in the
DNA code of a living
organism
– DNA Extraction
• Open a cell (mechanical
and chemical methods)
• Use a chemical to separate
the DNA from the rest of
the cell parts (an alcohol)
13-2 Manipulating DNA
– Cutting DNA
• DNA molecules are
very long
• Restriction enzymes
– Enzymes that cuts
DNA at a specific
sequence of
nucleotides
• Sticky ends – these
are the cut ends of
the DNA
13-2 Manipulating DNA
– Separating DNA
• Gel electrophoresis
– A mixture of DNA
fragments is placed at
one end of a porous
gel (negative end), and
an electric voltage is
applied to the gel
– The molecules will
move from negative
to positive
13-2 Manipulating DNA
13-2 Manipulating DNA
• Using the DNA
Sequence
– Once it is separated
it is manageable
• It can now be
– Read
– Studied
– Changed
13-2 Manipulating DNA
– Reading the
Sequence
• How do you read
unknown DNA?
• You can use:
– DNA Polymerase
– Four nucleotides
– Chemical markers
13-2 Manipulating DNA
– Cutting and Pasting
• DNA synthesizers
– Enzymes join artificial
pieces of DNA with
natural pieces
– Recombinant DNA
• Enzymes join genes
from one strand of
DNA with genes
from another strand
of DNA
13-2 Manipulating DNA
• Making Copies
– PCR or Polymerase
chain reaction
• Photocopying DNA
over and over
• Use strands of DNA
that are called
primers
13-3 Cell Transformation
• Transformation
– When a cell takes
in foreign DNA
and joins it with
the existing
DNA
– This external
DNA becomes
part of the cells
DNA
13-3 Cell Transformation
• Transforming Bacteria
– Foreign DNA is joined
to plasmid
• Plasmid – small, circular
DNA molecule
• Genetic marker – a gene
that makes it possible see
which bacteria are
carrying the plasmid (that
is marked) and which
bacteria are not.
13-3 Cell Transformation
• Transforming Plant Cells
– Using bacterium that
normally infect plant cells
and cause tumors
– Taking away the cell wall
some plant cells will take
up DNA on their own
– If successful recombinant
DNA will be found in a
chromosome of the cell
13-3 Cell Transformation
• Transforming Animal
Cells
– DNA can be injected
directly into the
nucleus of an egg
– Enzymes help insert
the new DNA into the
eggs existing DNA
– New DNA contains
markers that tell which
cells picked up the
DNA
13-4 Applications of Genetic
Engineering
• Transgenic Organisms
– Organisms that contain
genes from other
species
– Firefly and tobacco
plant
– Genetic engineering has
increased the growth of
biotechnology
13-4 Applications of Genetic
Engineering
– Transgenic
microorganisms
• Bacteria reproduce
quickly
• Uses:
– Can grow human
proteins
• Insulin, growth
hormone, and
clotting factor
13-4 Applications of Genetic
Engineering
– Transgenic Animals
• Mimic human body for
testing
• Faster growing animals
• No more food poisoning
• Grow human proteins
13-4 Applications of Genetic
Engineering
13-4 Applications of Genetic
Engineering
– Transgenic Plants
• Natural insecticide
• Resist weed killing
chemicals
• Food resistant to
spoiling
• Weather resistant plants
• Grow vitamins or
proteins
13-4 Applications of Genetic
Engineering
• Cloning
– Clone - A member of
a population of
genetically identical
cells produced from a
single cell
– Dolly – The cloned
sheep from 1997
– Save endangered
species