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Selective Breeding. Mrs. Wach. Selective Breeding. This is the oldest type of genetic manipulation. Breeding organisms for a desired characteristic. Works very well in plants. Also works with animals, but this can be more difficult. Selective Breeding.
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Selective Breeding Mrs. Wach
Selective Breeding • This is the oldest type of genetic manipulation. • Breeding organisms for a desired characteristic. • Works very well in plants. • Also works with animals, but this can be more difficult.
Selective Breeding • Mating animals to produce desired traits in offspring • Racehorses • Dog breeds • Chickens • Variegated roses • Giant pumpkins • Seedless fruits
Inbreeding • Inbreeding involves crossing two closely related individuals that have similar desirable characteristics. • Inbreeding produces organisms that are genetically similar. • When inbred organisms are mated, the change of their offspring inheriting two recessive alleles increase. This can lead to genetic disorders.
Pure-Breed Animals • Dogs, Cats, Horses, etc. • End up with many problems- joint issues, blindness, etc. • “Mutts” are often more healthy
Hybridization • In hybridization, breeders cross two genetically different individuals. (Remember, a hybrid organism has two different alleles for a trait.) • The hybrid organism that results is bred to have the best traits from both parents. Horse + Donkey = Mule
Hybridization • Liger is another example
Take this just a step further • Scientists can hybridize the genes by adding DNA from one organism to another organisms egg (meta-cloning) • Example: chickens that are both meaty and good egg layers
Cloning: Plants • Cloning is used to produce offspring with desired traits. • A clone is an organism that has exactly the same genes as the parent. • It is not hard to clone certain plants, like African violets. Just cut a stem from the plant and put the stem in soil. Water it, and soon a new plant grows—being genetically identical to the parent plant.
Cloning: Ethics Issue • Dolly was the first mammal to be cloned from an adult. • The cell from the donor was taken from a mammary gland. • Dolly had three mothers: one provided the egg, another the DNA and another carried her to term. • Dolly lived for six years and died from a common sheep lung disease. Others in her heard were infected. (Normal life expectancy for a sheep is 10-12 years.) Dolly the Sheep (right) 5 July 1996 – 14 February 2003
Genetic Engineering Genetic engineering is the deliberate, controlled manipulation of the genes in an organism with the intent of making that organism better in some way. Scientists use genetic engineering techniques to insert human genes into the cells of cows. The cows then produce milk containing the human blood-clotting protein needed by people with hemophilia.
Genetic Engineering in Bacteria DIABETES: The DNA ring in a bacteria cell is spliced and the human gene for insulin production is inserted into it. Now, all future bacteria cells are capable of producing insulin.
Genetic Engineering in Plants Genes have also been inserted into the cells of plants, such as tomatoes and rice. Some of the genes enable the plants to survive in cold temperatures or in poor soil. Other genetically engineered crops can resist insect pests or contain more nutrients.
Genetic Engineering Gone Too Far? • Genetic engineering is the deliberate, controlled manipulation of the genes in an organism with the intent of making that organism better in some way.
Gene Therapy • Gene therapy is the genetic engineering that involves inserting copies of a gene directly into a person’s cell to treat genetic disorders in human.
