Download Genetic Technology

Genetic Technology
Q: How can desired traits reappear generation after generation?
A.
1. Selective Breeding:
 Increasing the frequency of a desired allele within a population
by forcing 2 organisms with the desired trait to mate
 Ex. Pure bred dogs, race horses, flowers
 Problem: takes a long time (the time it takes for reproduction
and development)
 Solution: Genetic Engineering
2. Genetic Engineering:
 Involves combining the desired genes (pieces of DNA) from one
organisms and inserting this DNA fragment into the DNA of the
host organism
 Faster, more reliable method of increasing the frequency of a
desired trait
a. Recombinant DNA:
 DNA that contains genes or DNA fragments from another
organisms
 DNA has be combined
b. Transgenic Organism:
 Organisms that contain recombinant DNA
 Ex. Glowing Tobacco: tobacco plants contain a piece of
DNA from a firefly
 Ex. Insulin Producing Bacteria: bacteria that contain the
human gene for producing insulin
 Ex. Pest Resistant Plants: plants that contain a gene to
produce their own pesticide
 Ex. Human Growth Hormone Producing Bacteria: bacteria
that contain the gene for producing human growth hormone
c. Process for Making Recombinant DNA:
1. Cleave DNA
 cut the desired gene (DNA sequence) using a restriction
enzyme as well as the host DNA
 Restriction enzymes are proteins used to cut DNA between
certain neulceotides on both strands of DNA
 There are many different restriction enzymes that are
specific for different genes (DNA sequences)
2. Cleave the Plasmid
 Plasmid: circular DNA found in bacterial cells
 You must cut open the circle DNA before you can
insert the desired gene
3. Gene Splicing
 Connecting the cleaved gene to the host DNA or plasmid
creating recombinant DNA
4. Cloning:
 The host cell (bacterial, plant, animal) can go through
mitosis making many copies of the recombinant DNA
 Once this new DNA is spliced the cell can produce the
new trait as well as the organism it will grow into
B. Human Genome Project
 Process to identify where the 80,000 genes are located on each of the 46
chromosomes
 Determine the sequence of the 3 billion nitrogen bases
Importance:
1. Diagnosing genetic disorders
2. Gene Therapy:
 Insertion of the normal genes into faulty cells containing to
correct a genetic disorder
 Ex. Cystic Fibrosis: insert the normal gene for lung function into
the cells of the diseased lungs in order for them to repair
themselves
3. DNA Fingerprinting
 DNA is cut with restriction enzymes into different length
fragments (# of nitrogen bases long)
 Fragments are (-) negatively charged
 When placed on a gel you get a very unique and individual
picture “fingerprint” of your DNA pattern
Gel Electrophoresis
 Process by which the DNA fragments are put into a gel with
electricity running through it forcing the (-) charged
fragments to move towards the (+) end of the gel box
 The smaller the fragment the faster it moves, the larger the
fragment the slower it moves
 Used for crime scene analysis, paternity testing (a child’s
DNA will come ½ from mother and ½ from father), and to
show evolutionary ancestry
4. Karyotyping
 A picture of the chromosome from one cell in order to determine if
there are any chromosomal mutations such as Down syndrome
5. Cloning
 Process of creating an identical organism
 Process:
a. Remove the nucleus from a body cell (diploid)
b. Remove the nucleus from an egg cell (haploid) and replace
it with the body cell nucleus
c. Implant the egg into the uterus of the female and allow the
diploid cell to go through normal development
d. Used to possible create new organs