1. Genetic Technology
CH 13

2. Applied Genetics
Selective breeding - produces organisms with desired traits.
1. Takes time, patience and several generations.
2. Increases the frequency of desired alleles.

3. Inbreeding – develops pure lines.
1. Mating closely related individuals.
2. Results in offspring that are homozygous for most traits.
3. Can bring out harmful, recessive traits because there is a greater chance that two closely related individuals both carry a harmful recessive allele for the trait.
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4. Hybrids
Hybridization – crossing parents with different forms of a trait.
Plants produced from crossing two cultivars often bigger and better.
Animals – when two species are crossed sterile hybrids are produced.
Zorse – cross between a horse and a zebra.

5. Determining Genotype
A test cross is done to determine the genotype of an unknown dominant individual.
1. A dominant phenotype can be homozygous or heterozygous.
2. Cross the unknown to a homozygous recessive. If any of the offspring are recessive, you know the unknown is heterozygous.
Homozygous recessive dd
Unknown
Unknown is Dd
Unknown is DD

6. Genetic Engineering
Faster and more reliable than traditional, selective breeding methods
Recombinant DNA – connecting or recombining fragments of DNA from different sources
Transgenic Organisms OR Genetically Modified Organisms (GMOs) – plants and animals that contain foreign DNA

8. Creating GMOs Three-step process
Restriction enzymes cut, or cleave, the DNA
If same enzyme is used to cleave DNA in two different organisms, the DNA pieces will stick together
“Sticky ends” are key to recombinant DNA
Vectors transfer DNA to host cell
Biological – viruses and plasmids
Mechanical – micropipettes and gene guns

9. FYI - More Info on Gene Gun

10. 3. DNA is rejoined by gene splicing
Transferred to host by one of the vectors
Duplicates as host cell divides

11. GMOs in Agriculture
Soy and corn are the most widely modified organisms in agriculture.
Both are very important to our economy!

12. GMOs in Agriculture
Different GMOs have different types of resistance – depends on what genes have been recombined in the organism
Herbicide resistance – Hra gene from tobacco plant
Insect resistance – genes from Bacillus thuringiensis (Bt) bacterium
Drought resistance

13. Pros and Cons The Good The Bad
GMOs can save farmers money – herbicides and lost crops (death) are costly!
Potential solution to world hunger – feed the growing human population
The Bad
Weeds developing herbicide resistance
Insects developing insecticide resistance
Arms race against mother nature?!

14. Testing for GMOs DNA extraction Polymerase Chain Reaction (PCR)
Method of replicating DNA outside of living organisms.
Essential for analysis of DNA.
Has allowed molecular genetics to become part of criminal investigations.
Gel Electrophoresis
used to separate the DNA pieces cut with restriction enzymes by size

16. Applications of DNA Technology
Cloning of organisms, as well as genes.
Pure DNA for study of specific genes from PCR.
Recombinant bacteria.
a. industrial use – break down pollutants.
b. medical use – produce hormones, insulin or.
amino acids.
c. agriculture
Transgenic animals – scientists can create animals with human diseases and animals that can produce human materials.

17. Transgenic plants – have been engineered to resist herbicides, produce internal pesticides and increase their protein production.

18. Human Genome
The Human Genome Project – has mapped and sequenced all human genes.
A. We have a linkage map.
,000 genes on chromosomes.
2. We know where the genes are located, but do not know the function of all genes.

19. Applications of the Human Genome Project
Diagnosis of genetic disorders followed by gene therapy.
A. Insertion of normal genes into human cells to correct genetic disorders.
B. fetal diagnosis and therapy.

20. A. Criminal investigations.
DNA Fingerprinting – no two individuals have the same DNA fingerprint, except identical twins.
A. Criminal investigations.
B. Identification of family members, dead or alive.

21. Stem Cells
Stem cells are unspecialized cells that continuously reproduce
Have potential to differentiate into one or more types of specialized cells
Identical stem cells
Stem cell
SELF-RENEWAL
(copying)
Stem cell
Specialized cells
DIFFERENTIATION
(specializing)

22. Embryonic stem cells
New research is looking into how to obtain stem cells from adult somatic (body) tissue and where they are located
Somatic stem cells can be found in brain, bone marrow, peripheral blood, blood vessels, skeletal muscle, skin, teeth, heart, gut, liver, ovarian epithelium, and testis