Chapter 13: Applied Genetics
Make Vocabulary Cards of the following terms (HWK): Selective breeding, Inbreeding,
Pure breeds, Genetic Engineering, Recombinant DNA process, Transgenic organism,
restricted enzyme, mechanical vector, biological vector, plasmids, gene cloning, clones,
Polymerase chain reaction (PCR), Sequencing DNA, Gel electrophoresis, Recombinant
DNA, The Human Genome Project, Linkage mapping, Gene therapy, and DNA
Fingerprinting
Notes
Selective Breeding is a long process to obtain a desired trait.
 Requires time, patience, and several generations of offspring to
 The breeder needs to choose the parents and the alleles must be known in
advance by using Punnett Squares
Inbreeding is the mating of closely related individuals
 Helps eliminate any undesired traits
 Only problem is recessive traits that could be harmful or even kill (lethal
traits) the organism
 Offspring are homozygous for most traits
 Pure breeds-is a selected group of organisms within a species that has been
bred because of a specific characteristic they portrait
Hybrids plants can increase productivity of food for humans because it is usually bigger in size
and has more nutrients
Genetic Engineering is a faster and more reliable method for increasing the frequency of a
specific allele in a population
 The DNA is cut or cleaved from one organisms into small fragments and
inserting the fragments into a host organism of the same or different species
 Another method is referred to as Recombinant DNA
 This is made my connecting fragments of DNA from different sources
 In the process Recombinant DNA can be inserted into a host organism’s
chromosomes and the organism
 Plants and animals using traits from a different genus –Transgenic
organism because some of their DNA is foreign to them
o Example Glowing tobacco plant seen on p. 341-Tobacco
plant contains a gene from a firefly
 The 1st step is to find a foreign DNA fragment to be
inserted
 After the DNA is isolated, the fragments are
cut from a chromosome with restricted
enzymes
o Restricted enzymes are bacterial
proteins that have the ability to cut
1


both strands of DNA molecule at a
specific nucleotide sequence (There
are 100’s)
nd
2 –is to attach DNA fragment to a carrier
 A vector –Is the means of how the DNA
fragments can be carried to the host cell,
o Vectors can be biological or
mechanical
 Mechanical vectors carry
foreign DNA into a cell’s
nucleus
 Biological vectors are
bacterial DNA, viruses, or
plasmids
**Plasmids are small ring of
DNA found in a bacterial
cell where the large ring is
the bacterium’s
chromosome
3rd –transfer into the host organism
 The plasmid or foreign DNA are cut with
the same restriction enzyme then the ends
will match and they will join together
reconnecting the plasmid ring
Gene cloning –The process where clones of genes are made.
 Clones are genetically identical copies
o Each identical recombinant DNA molecule is called a gene clone
o In 1997, Dolly was the 1st mammal (sheep) cloned
Polymerase chain reaction (PCR) is the process allowing replication of DNA outside living
organisms in a special machine
 Heat is used to separate the DNA strands from one another
 An enzyme isolated from a heat-loving bacterium is used to replicate the DNA when the
appropriate nucleotides are added to the PCR machine
 The machine replicates millions of copies of DNA in less than a day
 Thermocycler are the copies of DNA cycled over and over again
 This process is valuable in biological for genetic research and finding diagnosis of
infectious diseases like AIDS and forensic labs especially in crime scenes
Sequencing DNA
This is another application used in genetic engineering to provide information about gene
mutations
 PCR is used first to replicate the million copies
 Then, the strands are separated from one another
2




The single-stranded fragments are placed in four different test tubes, one for each
DNA base.
Each tube contains four normal nucleotides (A, C, G, T) and an enzyme that can
catalyze the synthesis of a complementary strand
One nucleotide in each tube is tagged with a different florescent color.
This reaction produces complimentary strands of varying lengths and then
separated by Gel electrophoresis (see p. 346)
o
DNA sequencing can be done only on small pieces of DNA. Gel
electrophoresis separates the small pieces from the large ones before
sequencing can occur
 Recombinant DNA is also used in medicine such as the making of large quantities of insulin
for Diabetic patients, and understanding how certain diseases work and developing cures
such as pituitary dwarfism, developing better crops and learning specific genes of organisms
including humans
The Human Genome Project (HGP) was developed in 1990 in the United States
o This was an international effort that was published in Feb. 2001
o The mission was to completely map and sequence every human gene and
chromosome in humans.
o It revealed the 46 chromosomes and 35,000-40,000 genes
o Application of this project will help diagnosis genetic disorders and possible cure
them
Linkage maps shows the position of genes on a chromosome
Gene therapy is the insertion of normal genes into human cells to correct genetic disorders.
 SCID (Severe Combined Immunodeficiency Syndrome) gene theory is during being tried
with much success
o Bone marrow cells are removed from a patient’s hipbone and grown in flask.
o Genetic engineered viruses containing a normal SCID gene are added.
o The bone marrow cells insert the normal gene into their DNA.
o When modified then the cells are returned to the patient’s bone marrow
o Gene begins to work
DNA Fingerprinting
 It works because no two individuals (except identical twins) have the same DNA sequences,
and because all cells (except gametes) of an individual have the same DNA
 Gel Electrophoresis is used in Forensics
______________________________________________________________________________
Bell Ringer BioTechnology “New Vaccines”
on p. 356
 Read the article
 List and briefly describe the three new types of vaccines
3