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Identical twins are two individuals that are genetically identical. What does this mean? How can a sheep that is 12 years old have an identical twin who is 4 years old?.
Identical twins are two individuals that are genetically identical. What does this mean?
Anyone who had never seen dogs before might assume that the breeds were different species: the greyhound so fast; the schnauzer’s hunting ability; the German shepherd’s intelligence and loyalty. How did they become so different?
American Luther Burbank (1849 – 1926) developed more than 800 varieties of plants including the disease-resistant Burbank potato that saved many from starvation.
What are the risks?
(i.e.: development of hundreds of useful bacteria strains, polyploid plants)
Genetic Engineering is the making of changes in the DNA code of a living organism, on purpose.
Geneticists can now remove DNA, read it, make a change to the code and then replace the DNA.
1. DNA Extraction: DNA is removed from the cell by one of many simple chemical procedures.
(You did it.)
3.Gel electrophoresis: A mixture of DNA fragments is placed at one end of a porous gel and an electric voltage is applied to the gel. When the power is turned on, DNA molecules, which are negatively charged, move toward the positive end of the gel. The smaller the DNA fragment, the faster and farther it moves.
When DNA synthesis is completed, there are many different dye-tagged strands of different lengths.
The DNA fragment which is to be copied is heated, which separates the strands, allowing the primers to bind to a single strand, then cooled.
The DNA polymerase used in this process has to be heated and cooled repeatedly. (It comes from an ancient bacteria living in the hot springs of Yellowstone National Park.)
Plasmids have 2 characteristics that make it relatively easy to replicate foreign DNA:
1. By transforming plasmids from bacteria and then introducing those bacteria into the plant cells.
2. By removing the plant cell’s walls. Sometimes these plant cells will then take up the foreign DNA on their own.
3. DNA can sometimes be injected directly into the cells.
If a method is successful and transformation occurs, the recombinant DNA is integrated into one of the chromosomes of the cell.
- Can be injected onto an egg cell
Watch this video carefully; it moves along pretty quickly but really does demonstrate how cloning is accomplished.
How to clone a sheep
The next video provides a discussion of the state of the technology and results of cloning and introduces some ethical issues that society faces with regard to cloning (and other genetic engineering techniques).