Selective Breeding Genetics & Heredity. Selective Breeding Open up your classwork notebooks...
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Transcript of Selective Breeding Genetics & Heredity. Selective Breeding Open up your classwork notebooks...
Selective Breeding
Genetics & Heredity
Selective Breeding
• Open up your classwork notebooks– Title: Selective Breeding– Date: 04/20/23
Objectives for today
• 1. Define selective breeeding
• 2. Differentiate between the types of selective breeding.
• 3. Define inbreeding, cloning, genetic engineering, and hybridization.
Warm-Up
• When we created our children (either SpongeBob of Sesame Street genetics), were you able to select which male gamete fertilized the female gamete?
• Why or why not?
• Is it possible for parents to select which male gamete will fertilize which female gamete/
Warm-Up Activity
• Take the next few minutes to think about what selective breeding means.
• When you think you have a definition for selective breeding write it down in your notebook.
• After your definition write down a few examples of selective breeding.
Definition
• Selective Breeding- the process of selecting organisms with desired traits to be parents of the next generation.
• This definition is rather technical so let’s come up with a definition that is more user-friendly.
Examples of Selective Breeding
• What are some of the examples of selective breeding that you were able to come up with?
• As we go over these examples make sure to write them down in your notebooks.
Examples of Selective Breeding
• Images from: google.com
Types of Selective Breeding
• For example: A farmer might cross a male and female turkey that are both plump and grow quickly.
• Why would a farmer choose to cross these two turkeys?
• What could be the down side of crossing these two birds, if they are genetically similar?
Types of Selective Breeding
• Cloning- creating organisms that have exactly the same genes as the organism from which it was produced.
• What is an example of cloning that’s occurred in the past 20 years?
Dolly the Sheep
• In 1996, a group of scientists were able to clone a sheep.
• The resulting cloned sheep was named Dolly.
• Dolly was remarkable because she was the first mammal to be succesfully cloned.
How they cloned Dolly
Image from www.science.howstuffworks.com
Issues with Dolly
• Dolly was able to produce 5 offspring in her lifetime.• However, in 2001 Dolly developed arthritis. This onset of
arthritis was early for a normal sheep.• In 2003, Dolly was euthanized because of her arthritis
and a progressive lung disease.• Dolly’s breed of sheep typically live up to 11-12 years
old, where Dolly only lived to be 6 years old.• Scientists are unsure if Dolly developed these symptoms
because she was a clone or due to some other factor.
Issues with Cloning
• What could be some possible issues with cloning, scientifically speaking?
• Think of Dolly’s early onset of arthritis.
• Cloning is common occurrence in plants and bacteria.
• Image from starwars.wikia.com
Types of Selective Breeding
• Genetic Engineering- genes from one organism are transferred into the DNA of another organism.
• This technique is used to help produce medicines and improve food crops.
• Example: scientists have been able to insert genes into tomato and rice plants that enable the plants to survive in cold temperatures or poor soils.
• What could be the benefit for genetic engineering, in the case of the plants?
Genetic Engineering
• Genetic engineering is on the forefront for medical treatments.
• Doctors have used the practice of gene therapy, inserting copies of a gene directly into a person’s cells, to treat diseases.
• For example, doctors could be able to treat hemophilia by replacing the defective allele on the X-chromosome.
Issues with Genetic Engineering
• People are concerned with the long term effects of genetic engineering.
• They fear that genetically engineered crops might not be safe, they may cause harm to the environment or cause health issues in humans.
• How would scientists be able to adress these concerns?
Types of Selective Breeding
• Hybridization- the crossing of two genetically different individuals.
• A hybrid organism is formed to have the best traits from both parents.
• What is an example of hybridization that you have learned about in the past few years?
Extend your knowledge
• We have now covered four different forms of selective breeding.
• In your notebooks write a paragraph on whether or not you agree with selective breeding. Make sure to have at least 2 pros and cons supporting your reasoning.
• Make sure to use your genetics and heredity vocabulary terms.
Back to Hybridization
• The American Chestnut Project
• What is the main goal of the American Chestnut Foundation (ACF)?
• Image from gatacf.org
American Chestnut
• What caused a decline in American Chestnut trees? (There are multiple reasons)
• What two species of Chestnuts are being crossed?
• What are the desirable traits that the ACF are trying gain from both species of Chestnuts?
• What steps are currently being taken to help revive this tree species?
American Chestnut
• You will be given an exit ticket on the American Chestnut project.
• This sheet must be filled out before you can leave the classroom.