Genetics & Biotechnology - Biology-RHS


14 Δεκ 2012 (πριν από 4 χρόνια και 7 μήνες)

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Chapter 13

Selective Breeding

is used to produce
organisms with desired traits

Dogs have been breed for hundreds of
years to do certain tasks : Saint Bernard

Keen sense of smell, Husky

to run long distances, German shepherd

high trainability

Two types of breeding patterns in Selective


used to give organisms a
competitive edge. Organisms can be bred
to be more disease
resistant, produce
more offspring, or grow faster


process in which two closely
related organisms are bred to have the
desired traits; to eliminate the undesired
ones in future generations

Genetic engineering

is used to manipulate the DNA of
one organism in order to insert exogenous DNA (the
DNA of another organism)

Researchers have inserted a gene for a bioluminescent
protein called green fluorescent protein (GFP) into
several different organisms; these organisms then glow
green under a black light


is the total DNA present in the nucleus of
each cell.

Restriction enzymes

are enzymes that recognize and
bind to specific DNA sequence and cleave the DNA
within that sequence

They are used as powerful tools for isolating specific
genomic DNA, it creates fragments of different sizes that
are unique to every individual

Gel Electrophoresis

uses an electric current to separate
the DNA fragments according to the size of the

Smaller fragments move farther faster than the larger

When DNA fragments are separated by gel
electrophoresis, specific fragments can be removed
and combined with DNA fragments from another
source this is called
Recombinant DNA

Recombinant DNA allows scientists to study
individual genes


are small, circular, double
stranded DNA
molecules that occur naturally in bacteria and yeast

DNA ligase is used to join the two DNA fragments


is used to make millions of copies of a specific
region of a DNA fragment

PCR is useful because this single DNA molecule then
can be copied, or amplified, numerous times to be
used for DNA analysis

Transgenic Organisms

are genetically engineered by
inserting a gene from another organism into another

Transgenic animals, plants, and bacteria are used not
only for research, but also for medical and