Chapter 13: Applied Genetics

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

Purebreeds-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
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
Restricted enzymes are bacterial proteins that have the ability to cut both strands of DNA molecule at a specific nucleotide sequence (There are 100’s)
2nd –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,
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
Each identical recombinant DNA molecule is called a gene clone
In 1997, Dolly was the 1stmammal (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
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)
DNA sequencing can be done only on small pieces of DNA. Gel electrophoresisseparates 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

This was an international effort that was published in Feb. 2001
The mission was to completely map and sequence every human gene and chromosome in humans.
It revealed the 46 chromosomes and 35,000-40,000 genes
Application of this project will help diagnosis genetic disorders and possible cure them

Linkage mapsshows 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

Bone marrow cells are removed from a patient’s hipbone and grown in flask.
Genetic engineered viruses containing a normal SCID gene are added.
The bone marrow cells insert the normal gene into their DNA.
When modified then the cells are returned to the patient’s bone marrow
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