1. Chapter 13
Gene Technology

2. Section 1: Vocabulary Pretest
Strand of RNA labeled with a radioactive element or fluorescent dye
Exact copy of a DNA fragment, a whole cell, or a complete organism
Enzyme that cuts DNA
Small rings of DNA inside bacteria cells
Pattern of DNA bands used for identification
Process that separates DNA fragments according to size
DNA from two different sources is combined
Technique that quickly produces many copies of DNA fragments
Small pieces of DNA needed to start DNA replication
Variations in the length of a DNA molecule between known genes
Repeating sequences of DNA
Viruses or plasmids used to carry DNA fragments
Altering genetic material in order to make new substances
Length Polymorphism
Variable number tandem repeats
Polymerase chain reaction
Primer
Restriction enzyme
Gel electrophoresis
DNA fingerprint
Genetic engineering
Recombinant DNA
Clone
Vector
Plasmid
Probe

3. Section 1 Vocab Answer Key
Length Polymorphism J
Variable number tandem repeats K
Polymerase chain reaction H
Primer I
Restriction enzyme C
Gel electrophoresis F
DNA fingerprint E
Genetic engineering M
Recombinant DNA G
Clone B
Vector L
Plasmid D
Probe A

4. DNA Technology
DNA Technology is the manipulation of DNA for practical purposes such as:
Identification using DNA fingerprinting
Improving food crops
Identifying genetic diseases before symptoms appear
Research for cures or treatments of genetic diseases

5. DNA Identification
About 0.1% of human DNA differs from person to person. This variation allows us to:
Identify people
Determine paternity
Identify human remains
Tracing human origins
Provide evidence in criminal cases

6. Noncoding DNA 98% of our DNA does not code for any protein
It is called noncoding DNA
It contains many length polymorphisms (variations in the length of the DNA molecule between known genes)
It also contains short, repeating sequences known as variable number tandem repeats (VNTR)
Geneticists use VNTR’s to determine how rare a particular DNA profile is.

7. Steps in DNA Identification
Isolate the DNA (make copies if needed)
Cut DNA into shorter fragments that contain known VNTR areas
Sort the DNA by size
Compare the size fragments in the unknown sample of DNA to those of known samples of DNA

8. Copying DNA: PCR
Polymerase Chain Reaction (PCR) is a technique that quickly produces many copies of a DNA fragment (it is used if the DNA fragment is very small)
Steps:
Start with a fragment of DNA with the sequence to be copied
Heat to denature and separate the DNA strands
Add primers (artificially made pieces of single-stranded DNA that are complementary to the ends of the DNA fragment); DNA polymerase; and nucleotides
Primers will bind to original strands; DNA polymerase will add free nucleotides to complete the strands
Repeat about 30 times and generate millions of copies

10. Cutting DNA
Restriction Enzymes: bacterial enzymes that recognize specific short DNA sequences and cut them.
Cuts are usually asymmetrical and produce “sticky ends” so that other pieces of DNA with complementary sequences can bind to them.

11. Sorting DNA by Size
Gel Electrophoresis —technique that separates nucleic acids or proteins according to their size and charge
Steps:
Cut DNA with restriction enzymes
Place DNA into wells in a thick gel
Run electric current through the gel
Negatively charged DNA moves towards positive end of the current
Smaller fragments move faster and farther
Transfer DNA to a nylon membrane and add radioactive probes
Expose x-ray film to radiolabeled membrane to produce a DNA fingerprint

12. Comparing DNA
At least 13 VNTR loci comparisons are needed to make a positive DNA identification.
Thirteen identical loci make the odds that two people will share a DNA profile about 1 in 100 billion

13. Recombinant DNA
Genetic engineering —the process of altering the genetic material of cells or organisms to allow them to make new substances. It often involves recombinant DNA
Recombinant DNA —DNA from one organisms is added to another
Pig expressing a jellyfish gene

14. Cloning Vectors
Clone —an exact copy of a DNA segment, a whole cell, or a complete organism: or to make a genetic duplicate
Vectors are used to clone DNA fragments
They carry foreign DNA from one organism to another
They include bacteriophages and plasmids

15. Plasmids
Plasmids —small rings of DNA found naturally in bacterial cells. They replicate separately from bacterial DNA

16. Plasmids serve as excellent vectors for DNA
Steps:
Isolate the plasmid from a bacteria cell and the DNA of interest from a human cell (ex: gene coding for insulin)
Used restriction enzymes to cut the DNA and the plasmid
Mix the DNA and the plasmid together; sticky ends will bond
Use DNA ligase to join them by forming permanent covalent bonds
Transfer the recombinant plasmids back into bacterial cells
Allow bacteria to reproduce (copying the plasmids to the new cells)
Use probes to identify the colonies that have the desired gene. These bacterial cells will now be able to produce human insulin

17. Probes
A probe is a strand of RNA or single-stranded DNA that is labeled with a radioactive element or fluorescent dye and that can base-pair to specific DNA, such as the donor gene in recombinant DNA.
Probes will glow under UV light, allowing scientists to identify which recombinant colonies have the desired gene.

18. Medical Applications for DNA Technology
Since 1982, more than 30 products made using DNA technology are now on the market.
Examples:
Human insulin
Proteins to treat immune system deficiencies and anemia
Clotting factors for people with hemophilia
Human growth hormone
Interferons for viral infections and cancer
Growth factors for treating burns and ulcers

19. Section 2 Vocabulary Pretest
Human Genome Project
Proteome
Single nucleotide polymorphism
Bioinformatics
Proteomics
An organism’s complete set of proteins
Combines biology, computer science and information technology
The study of all of an organism’s proteins
Unique spots in DNA where individuals differ by a single nucleotide
A research effort to sequence all of the human DNA code and locate within it all of the functionally important sequences (genes)

20. Answer Key Human Genome Project E Proteome A
Single nucleotide polymorphism D
Bioinformatics B
Proteomics C

21. The Human Genome Project
The Human Genome Project began in 1990
Its goal was to determine the sequence of all 3.3 billion nucleotides of the human genome and to map the location of every gene on each chromosome.
More than 20 labs in 6 countries worked on the project
It was completed in 2003
DARN

22. What Did We Learn? Only 2% of our genome codes for proteins
Chromosomes have unequal distribution of nucleotide sequences that are transcribe and translated
Our genome is smaller than we thought; only about 30, ,000 genes
The same gene can encode different versions of a protein. An organism’s complete set of proteins is called its proteome.
Transposons, pieces of DNA that move from one chromosome location to another make up half of our genome and play no role in development
The are 8 million single nucleotide polymorphisms (SNP). These are spots where individuals differ by just one nucleotide.

23. Applications
We have discovered the specific genes responsible for many diseases, which can help us to develop treatments and possibly cures for the more than 4,000 human genetic disorders

24. Section 3 Vocabulary Pretest
Gene therapy
Nuclear transfer cloning
Telomere
DNA vaccine
Bioethics
Vaccine made from DNA of a pathogen but does not have disease-causing capabilities
A method for cloning entire organisms
The study of ethical issues related to DNA technology
Repeated sequences of DNA at the ends of chromosomes
A technique used to treat genetic disorders

25. Answer Key Gene therapy E Nuclear transfer cloning B Telomere D
DNA vaccine A
Bioethics C

26. Genetic Engineering: Medical Applications
Gene Therapy —a technique used to treat a genetic disorder by introducing a gene into a patient’s cells. It works best for disorders that result from the loss of a single protein. Ex: Cystic Fibrosis

27. Cystic Fibrosis patients lack the CFTR gene: Result—excess mucus in lungs
Steps of Gene Therapy:
Isolate the functional gene from a healthy person
Insert it into a viral vector
Infect the patient with the recombinant virus (carrying the functional gene)
The functional gene temporarily produces the missing protein, improving the symptoms of the disease

28. Obstacles:
Cells that express the highest levels of CFTR are deep in the lungs and are not being reached by the virus
Surface cells die off regularly so the treatment must be repeated often
Immune reactions to the treatment may occur

29. Genetic Engineering: Medical Applications
Cloning —in 1996, the first clone of an adult mammal was developed. It was a sheep named Dolly.
Dolly was created by a process known as cloning by nuclear transfer
Steps:
Mammary cell with its nucleus was isolated from an adult female sheep
Egg cell from another sheep was isolated and the nucleus removed
The two cells were fused together and an embryo developed
Embryo was transferred into a surrogate mother
Dolly was born with nuclear DNA that was identical to the donor of the mammary cell
Professor Ian Wilmut and Dolly

30. Dolly suffered from premature aging and died at the age of 6
Dolly suffered from premature aging and died at the age of 6. However, other cloned
animals have not experienced the same problem.

31. Why Clone Animals?
Most animal cloning is done to alter the genome in some useful way.
Examples:
Altered, cloned goats can secret human blood clotting factors into their milk. This can then be extracted and used to treat hemophiliacs.
Cloned pigs are altered so that their organs can be used in human transplants with a lessened risk of rejection.
Altered, cloned mice are used in the study of many human diseases; like cystic fibrosis.

32. Genetic Engineering: Medical Applications
Vaccines —DNA vaccines are now being researched. They are made from the DNA of the pathogen, except the disease-causing genes are removed.
When injected into a patient, the patient will mount a defense and build up antibodies.
If the real, disease-causing pathogen then enters the body; the antibodies will attack— preventing illness.
DNA vaccines to prevent AIDS, malaria and certain cancers are currently being studied.

33. Genetic Engineering: Agricultural Applications
Genetically Modified (GM) Crops are becoming very common. Today, most crops can be genetically engineered to be:
More tolerant to environmental conditions
Resistant to weed killing herbicides
Resistant to insects and other pests
Resistant to diseases
Improve nutritional value

34. Ethical Issues
Bioethics —the study of ethical issues related to DNA technology.
Issues:
GM crops: are they healthy for us and are they safe for the environment?
Gene therapy: considered unethical if it involves reproductive cells that would affect future generations
Cloning: considered unethical to clone human embryos for reproduction
Genetic make-up of individuals should remain confidential to reduce the possibility of discrimination.