What does PCR stand for? What is it used for?
Polymerase Chain Reaction. It
is used to copy millions of a specific DNA sequence in a short time period.
What are the 4 materials used for PCR?
DNA to be copied, DNA polymerase, Large amount of nucleic bases, and two primers.
What is the purpose of a primer in PCR?
to act as a starting point for a new strand
Describe the 3 steps of PCR.
Separating: the container with all of the reactants is heated to separate the double stranded DNA into single strands. (heat replaces DNA helicase)
2. Binding: the container is cooled allowing primers to bind to their complementary DNA sequences.
3. Copying: the container is heated again and the polymerases begin to build new strands of DNA. Most polymerases are broken down by excessive heat, so the polymerases used for PCR come from bacteria that live in hydrothermal vents.
What is a DNA fingerprint?
A representation of the parts of an individuals DNA that can be used to identify a person at the molecular level.
Where are the greatest DNA differences found between individuals?
found in regions that are not part of genes, the non coding regions known as introns
What regions of DNA does DNA fingerprinting focus on?
Non-coding regions called introns
What is a clone?
A genetically identical copy of a gene or of an organism
What organisms can clone themselves? How?
Plants- Bacteria-binary fission, and Sea stars-fragmentation
Describe the procedure of nuclear transfer.
1. An unfertilized egg is taken from an animal and the egg’s nucleus is removed.
2. A nucleus from the cell of the animal to be cloned is implanted into the egg.
3. Electricity is used to stimulate the egg so it will start dividing.
4. After the embyro grows for a few days it is transplanted into a female.
What was the first adult mammal to be cloned?
Dolly, the sheep, in 1997. It took 276 times and the scientists were wilmut and cambell
What are some benefits associated with cloning?
Organs from cloned mammals can be used for transplantation in humans.
Endangered species could be saved by using clones to increase the population
What are some drawbacks associated with cloning.
The success rate in cloning mammals is very low- it takes hundreds of attempts to produce one clone which is costly and time consuming
2. Cloned animals have chromosomes that age prematurely making them more prone to disease as well as having problems in development an tend to become fatally oversized.
3. Cloned animals in the wild population would decrease diversity because the clones are all genetically identical
Define genetic engineering
the changing of an organism’s DNA to give the organism new traits.
What is recombinant DNA?
DNA that combines gens from more than organism
What are some uses for recombinant DNA?
To create crop plants that make medicines and vitamins, this process is called “pharming”. And to make vaccines against HIV, the virus that causes AIDS
What is a vector? What are some examples of vectors?
an agent that is used to carry a gene of interest into another cell
Examples: Plasmids, viruses and yeast.
What is the function of DNA ligase?
The enzyme that glues together the gene and the plasmid
How can scientists genetically alter plants? (there are 6 ways)
Make plants more tolerant to drought conditions and withstand frost
2. Create plants that can adapt to different soils, climates and environmental stresses.
3. Add enzymes which control how fast fruit ripen. This improves shelf life.
4. Improve the nutritional value.
5. Improve taste.
6. Make plants resistant to pests or insecticides. Plants are injected with a gene that destroys the gut of insects.
What are fishberries?
strawberries with an anti-freezing gene from flounder.
What is Golden rice? Explain where it is utilized and how it is “better” than regular rice.
rice is a major food source in Asia but has low levels of beta carotene and iron which is used to make Vitamin A. Therefore, many people in these cultures have poor vision and iron deficiencies. To counteract this, scientists add genes from other plants to enrich the rice.
What is BT corn?
corn produces a bacterial toxin that kills corn borer
What is a transgenic animal? What can they be used for?
animals that have one or more genes from another organism inserted into their genome Often used to produce human protein that is too complex to be made by bacteria or to create animals that can be used to model human development or disease.
Provide 2 examples of transgenic mice and how they are studied to learn about human diseases.
1. Oncomouse- genetically engineered to always develop cancer (scientists mutated a gene that controls cell growth).
*Researchers use the oncomouse to study cancer and anticancer drugs.
2. Gene knockout mice-by disrupting the function of a gene it can be purposely ” turned off “
What are some concerns about genetic engineering?
GM foods could have negative side effects on our health (allergic reactions)
GM plants may negatively affect the environment
What is genomics?
The study of genomes (all of an organism’s genetic information), which begins with determining the order of DNA nucleotides in genes (known as gene sequencing)
How is gene sequencing used?
The genomes of several plants have been sequenced to learn ways to improve crop yield and to increase crop resistance to disease and weather.
2. The genomes of rats and mice are similar to humans so they can be used as models for human diseases and gene function.
What were the 2 goals of the Human Genome Project?
To map and sequence all of the DNA base pairs of the 46 human chromosomes.
To identify all of the genes
What work still needs to be done?
Scientists continue to work on identifying genes, finding the location of genes, and determining the function of genes.
What is genetic screening?
is the process of testing a person’s DNA to determine their risk of having or passing on a genetic disorder.
What 2 procedures does genetic screening involve?
Pedigree analysis and DNA testing
What are some disorders that can be identified using genetic screening?
cystic fibrosis and Duchenne’s Muscular Dystrophy
What is gene therapy?
is the replacement of a defective or missing gene, or the addition of a new gene , into a person’s genome to treat a disease. (gene is delivered by a virus)
What are some challenges associated with gene therapy?
inserting the correct gene and regulating gene sequences
What diseases/disabilities can benefit from stem cell research?
Heart disease, Leukemia and other cancers, Rheumatoid arthritis, Parkinson’s disease, and type 1 diabetes.
What is the newest development made in stem cell research?
Adult skin cells have been turned into pluripotent cells, which have similar potential to embryonic stem cells.The process of creating these cells involves inserting genetic material that makes the cell run backwards