1. Section 15.1 Notes 2015
Revised on 1/28/15

2. Basic Vocab
Species – a group of organisms that can breed together and produce fertile offspring
Population – all of the individuals of a species that live in a certain area, at a certain time
Gene Pool – all of the genes, including all of the different alleles for each gene, that are present in a population

3. Selective Breeding
Selective breeding (also called artificial selection) is a way in which humans manipulate the gene pools of populations
Selective breeding – when humans select which organisms will reproduce/pass their genes to the next generation

4. Selective Breeding Human uses of selective breeding
-making new varieties of cultivated plants
-domestication of animals

5. Examples of Selective Breeding
Modern day corn is descended from a grass called teosinte
*Taken from

6. Examples of Selective Breeding
Dog Breeds – all breeds of dogs are descended from wolf-like ancestor *taken from

7. Selective Breeding Hybridization
-crossing dissimilar individuals to bring
together the best of both organisms
-the offspring are often hardier than the
parents
-many hybrids combined the disease
resistance of one plant with the food-
producing capacity of another

8. Selective Breeding Inbreeding
-the continued breeding of individuals with
similar characteristics
-inbreeding is used to maintain the desirable
characteristics in a line of organisms
-can be a risky practice because it increases
the chances that offspring will have two
recessive alleles for a genetic defect

9. Increasing variation
Biotechnology – the application of a technological process, invention, or method to living organisms
Selective breeding is considered a type of biotechnology
However, sometimes breeders want more variation than can be achieved through selective breeding

10. Increasing Variation Mutations – heritable changes in DNA
Mutations occur spontaneously in nature
Breeders can increase the mutation rate of an organism by using radiation or chemicals
Mutations are usually harmful to the organism but sometimes breeders can create mutations in organisms that are useful to humans

11. Increasing variation
The application of radiation or chemicals to create useful mutations has been very successful with bacteria
This technique has allowed scientists to develop hundreds of useful bacterial strains

12. Polyploid plants
Polyploid – organisms that contain more than two sets of chromosomes
Polyploidy in plants can naturally occur (it is rare in animals and if it does occur is usually fatal)
Drugs that prevent the separation of chromosomes during meiosis are very useful in plant breeding. These drugs can produce cells that have many times the normal number of chromosomes

13. Polyploid Plants
Polyploidy can quickly produce new species of plants that are larger and stronger than their diploid relatives.
Several important crop plants such as bananas and some citrus fruits have been produced this way

14. Polyploid Plants