1. End Show 13-1 Changing the Living World Slide 1 of 18 Copyright Pearson Prentice Hall Selective Breeding What is the purpose of selective breeding?

2. End Show 13-1 Changing the Living World Slide 2 of 18 Copyright Pearson Prentice Hall A New Breed The tomatoes in your salad and the dog in your backyard are a result of selective breeding. Over thousands of years, humans have developed breeds of animals and plants that have desirable characteristics. How do breeders predict the results of crossing individuals with different traits?

3. End Show 13-1 Changing the Living World Slide 3 of 18 Copyright Pearson Prentice Hall 1. Think of two very different breeds of dogs that are familiar to you. On a sheet of paper, construct a table that has the following three heads: the name of each of the two dog breeds, and “Cross-Breed. 2.The rows of the table should be labeled with characteristics found in both breeds of dogs. Examples might include size, color, type of coat, intelligence, aggression, and so on. 3.Fill in the column for each of the two dog breeds. In the column labeled “Cross-Breed,” write in the characteristic you would expect to see in a cross between the two breeds you have selected.

4. End Show 13-1 Changing the Living World Slide 4 of 18 Copyright Pearson Prentice Hall 1. Think of two very different breeds of dogs that are familiar to you. On a sheet of paper, construct a table that has the following three heads: the name of each of the two dog breeds, and “Cross-Breed. Encourage students to refer only to breeds with which they are familiar. 2.The rows of the table should be labeled with characteristics found in both breeds of dogs. Examples might include size, color, type of coat, intelligence, aggression, and so on. Additional traits might include shape of ears, shape of muzzle (pointed or square), or length of legs with respect to body. 3.Fill in the column for each of the two dog breeds. In the column labeled “Cross-Breed,” write in the characteristic you would expect to see in a cross between the two breeds you have selected. Students will likely assume that traits of the cross-breed are intermediate between those of the two parent breeds.

5. End Show 13-1 Changing the Living World Slide 5 of 18 Copyright Pearson Prentice Hall 13–1Changing the Living World A.Selective Breeding 1.Hybridization 2.Inbreeding B.Increasing Variation 1.Producing New Kinds of Bacteria 2.Producing New Kinds of Plants

6. End Show 13-1 Changing the Living World Slide 6 of 18 Copyright Pearson Prentice Hall Selective Breeding Selective breeding allows only those organisms with desired characteristics to produce the next generation. Nearly all domestic animals and most crop plants have been produced by selective breeding.

7. End Show 13-1 Changing the Living World Slide 7 of 18 Copyright Pearson Prentice Hall Selective Breeding Humans use selective breeding to pass desired traits on to the next generation of organisms.

8. End Show 13-1 Changing the Living World Slide 8 of 18 Copyright Pearson Prentice Hall Selective Breeding Hybridization Hybridization is the crossing of dissimilar individuals to bring together the best of both organisms. Hybrids, the individuals produced by such crosses, are often hardier than either of the parents. (Hybrid Vigor)

9. End Show 13-1 Changing the Living World Slide 9 of 18 Copyright Pearson Prentice Hall Selective Breeding Inbreeding Inbreeding is the continued breeding of individuals with similar characteristics. Inbreeding helps to ensure that the characteristics that make each breed unique will be preserved. Serious genetic problems can result from excessive inbreeding.

10. End Show 13-1 Changing the Living World Slide 10 of 18 Copyright Pearson Prentice Hall Increasing Variation Why might breeders try to induce mutations?

11. End Show 13-1 Changing the Living World Slide 11 of 18 Copyright Pearson Prentice Hall Increasing Variation Breeders increase the genetic variation in a population by inducing mutations.

12. End Show 13-1 Changing the Living World Slide 12 of 18 Copyright Pearson Prentice Hall Increasing Variation Mutations occur spontaneously, but breeders can increase the mutation rate by using radiation and chemicals. Breeders can often produce a few mutants with desirable characteristics that are not found in the original population.

13. End Show 13-1 Changing the Living World Slide 13 of 18 Copyright Pearson Prentice Hall Increasing Variation Producing New Kinds of Bacteria Introducing mutations has allowed scientists to develop hundreds of useful bacterial strains, including bacteria that can clean up oil spills.

14. End Show 13-1 Changing the Living World Slide 14 of 18 Copyright Pearson Prentice Hall Increasing Variation Producing New Kinds of Plants Mutations in some plant cells produce cells that have double or triple the normal number of chromosomes. This condition, known as polyploidy, produces new species of plants that are often larger and stronger than their diploid relatives. Polyploidy in animals is usually fatal.

15. End Show 13-1 Changing the Living World Slide 15 of 18 Copyright Pearson Prentice Hall which crosses consists of Selective Breeding for example Inbreeding Hybridization Similar organisms Dissimilar organisms for example Organism breed A Organism breed B Retains desired characteristics Combines desired characteristics which which crosses which Section 13-1 Concept Map

16. End Show - or - Continue to: Click to Launch: Slide 16 of 18 Copyright Pearson Prentice Hall 13-1

17. End Show Slide 17 of 18 Copyright Pearson Prentice Hall 13-1 The usual function of selective breeding is to produce organisms that a.are better suited to their natural environment. b.have characteristics useful to humans. c.can compete with other members of the species that are not selected. d.are genetically identical.

18. End Show Slide 18 of 18 Copyright Pearson Prentice Hall 13-1 Crossing a plant that has good disease- resistance with a plant that has a good food- producing capacity is an example of a.inbreeding. b.hybridization. c.polyploidy. d.crossing over.

19. End Show Slide 19 of 18 Copyright Pearson Prentice Hall 13-1 New species of plants that are larger and stronger are a result of a.monoploidy. b.diploidy. c.polyploidy. d.triploidy.

20. End Show Slide 20 of 18 Copyright Pearson Prentice Hall 13-1 The function of inbreeding is to produce organisms that a.are more genetically diverse. b.are much healthier. c.are genetically similar. d.will not have mutations.

21. End Show Slide 21 of 18 Copyright Pearson Prentice Hall 13-1 Increasing variation by inducing mutations is particularly useful with a.animals. b.bacteria. c.plants. d.fungi.