Lesson 10 Selective Breeding When you select or

Lesson 10: Selective Breeding When you select or choose which two parents to breed

• Have you ever watched a dog show? Many different breeds are presented. Judges look for the specific traits each type of dog should have. When breeding dogs what traits might be desired? § Bigger or smaller § Nose more round or pointed § Preferred color

Humans can affect the traits of organisms through selective breeding, or choosing certain characteristics to be passed on. This is called selective breeding.

If you were a corn farmer, what different traits might you look for in plants? Can you breed certain parents to get those traits?

• Inbreeding, breeding parents with the same traits over and over again, produces individuals with similar characteristics. This comes with some risks. Inbreeding increases the possibility that an individual will inherit two recessive alleles for a genetic defect.

• Here’s how selective breeding works. • Cavaliers have four different coat (hair) colors: Blenheim (white and brown), Ruby (solid brown), Brown & Black, and Tri-color (white, black and brown). • Their coat color depend on the traits they received from their parents.

I have a male, named Nicholas (Nick). He is Blenheim.

Chloe, the mom of the last litter of puppies, is Tri-Color.

The Puppy Count (heads and spines)

What will they look like? What is the puppy coat probability of Blenheim? _____ Tri-Color? ____ Hint: Nick’s coat color is dominate

• Hybridization is selective breeding that involves crossing individuals with different traits to obtain organisms with the best traits of each parent. These individuals are often more resilient than their parents.

EXAMPLES: a LIGER

a Zedonk

a Mule

selective breeding • the process through which humans use naturally occurring genetic patterns to pass desired traits on to generations of plants and animals

inbreeding • selective breeding in order to maintain a certain characteristic in a line of organisms

hybridization • selective breeding that involves crossing individuals with different traits to obtain organisms with the best traits of each parent

• Genetic engineering and cloning use technology to produce more cells or offspring. The first mammal cloned from an adult cell was a sheep named Dolly.

• Dolly’s birth was engineered by veterinary researcher Dr. Ian Wilmut and his colleagues at the Roslin Institute, and their achievement shattered the belief that adult mammal cells could not be used to recreate a genetic copy. • Dolly gave added impetus to talk — and concern — about human cloning.

ethics • the rules of conduct recognized in respect to a particular class of human actions or a particular group, culture, etc. • What is alright to do and what should never be done?

Human Reproductive Cloning Ethical Issues: • Technical and medical safety • Undermining the concept of reproduction and family • Ambiguous relations of a cloned child with the progenitor • Confusing personal identity and harming the psychological development of a clone • Concerns about eugenics • Contrary to Human Dignity • Promoting trends towards designer babies and human enhancement

• The cloning debate involves scientists, legislators, religious leaders, philosophers and international organizations, but not always harmoniously. General agreement (almost unanimously) is that human “reproductive” cloning — for the purposes of producing a human genetic-copy baby — is unethical.

genetic engineering • the process of removing a bit of genetic material from one organism and inserting it into another

cloning • the process of using the genetic information from a single cell of an organism to produce another organism with the same genetic information