Crossing dissimilar individuals to bring together the best traits of both organisms Produces hybrids * Hybrids can be different species crossed together or different types within the same species. Hybridization
Golden Doodle and Puggle Designer breeds or mutts?
Can you think of other fruit or vegetable hybrids? Pluot Broccoflower
Inbreeding Domesticated animals and plants are inbred to develop “breeds” and “varieties.” Researchers use inbred strains to assure genetic similarities in their experiments. Problems: it can increase the chance of unfavorable traits showing up. Golden retrievers - epilepsy Dalmations - hereditary deafness
Increasing Variation Breeders can increase variation in a population by inducing mutations Mutation = any change in DNA Mutations can happen randomly, as in this Scottish fold cat. Cat enthusiasts bred these cats from a single cat with a mutation for the ears. A new strain of Oil-eating bacteria was produced.
Mutations can produce new kinds of plants Ex: Plants can sustain multiple sets of chromosomes - Polyploidy.
Manipulating DNA Making any changes in the DNA code is: Genetic Engineering How DNA is Manipulated: Extract DNA from cells Cut DNA into smaller pieces (Restriction enzymes) Identify the sequence of bases in a DNA molecule (Gel electrophoresis) Make unlimited copies of DNA strands(PCR) Combining different strands of DNA from different organisms (recombinant DNA)
Transgenic Organisms Definition: Organisms that contain genes from another organism. Transgenic microorganisms – bacteria that produce human insulin. Transgenic plants – major part of US agriculture; weed resistance; insecticides Transgenic animals – growth hormones in livestock, resistance to bacterial infections, production of human proteins.
Transgenic animals Gene causes these mice to glow in the dark. Normally, the gene is found in jellyfish.
Putting bacteria to work for us. Using recombinant DNA The human Insulin gene is inserted into the bacterial DNA. The bacteria now produces human insulin at a much faster pace and cheaper than animals can.
Cloning Natural clones – identical twins DNA must be identical to be a clone. Lifespan usually shortened. Health problems multiplied. Chance of survival before birth low. 1997 Dolly the sheep cloned, 1 st mammal
A donor cell is taken from a sheep’s udder. Donor Nucleus These two cells are fused using an electric shock. Fused Cell The fused cell begins dividing normally. Embryo The embryo is placed in the uterus of a foster mother. Foster Mother The embryo develops normally into a lamb—Dolly Cloned Lamb Egg Cell An egg cell is taken from an adult female sheep. The nucleus of the egg cell is removed. Section 13-4 Figure 13-13 Cloning of the First Mammal