Aim How does selective breeding affect genetic variation

Aim: How does selective breeding affect genetic variation? Do Now: DNA Regents Questions HW #1: Selective Breeding

Meet the Super Cow 1. Describe the cow in the video clip. 2. What procedure produced this cow? 3. Describe the process of selective breeding. http: //www. youtube. com/watch? v=Nmkj 5 gq 1 c. QU

Engineer a Crop: Selective Breeding http: //www. pbs. org/wgbh/harvest/engineer/select. html • In the past, farmers saved their best seeds and planted them the following growing season. By doing so, the next season’s crops would be slightly bigger, or sweeter, or more resistant to disease. The change was slight, but over many generations, crops did change significantly. • Hypothesize: If you keep selecting the seed from the biggest ear of corn, what should happen to the overall size of the corn as you move through each growing season?

Selective Breeding • Use natural reproduction to obtain desired characteristics –Select for desirable traits in offspring by choosing organisms of the same species to mate

Real Life Examples of Selective Breeding • Dairy farmers may choose to mate only cows that give the most milk • Seedless Fruit Hypoallergenic Cat • Purebred Animals • Wild Mustard Plant

Real Example of Selective Breeding Hybrid = + Horse Donkey Mule Big, Fast, Excitable Small, Slow, Calm Strong, Endurance, Calm

Real Example of Selective Breeding In 1872, Luther Burbank developed a new potato. While trying to improve the Irish potato, Burbank developed a hybrid that was disease resistant. He introduced the Burbank potato to Ireland to help combat the potato famine. Disease Resistant Potato Disease resistant potato + Food-producing potato Burbank hybrid

Advantages: Disadvantages: • Desirable traits • Decreases variation • Resistance to disease • Seedless fruit • Bigger crops • Recessive genetic disorders increase • Ex. Hip dysplasia in certain dog breeds.

Aim: How can DNA be Used to Create Genetically Identical Individuals? Do Now: Selective Breeding Do Now HW #2: Cloning

Cloning and the Tasmanian Tiger

Clone • An organism that is genetically identical to the organism from which it was produced. • Asexual Reproduction

Animals that Have Been Cloned • • • Sheep (Dolly) Cat (Beaker) Frog Salamander Mouse Hello Dolly!!

How is Cloning Done? 1. The nucleus of a body cell from the desired organism is removed. 2. An egg cell from an adult female sheep is removed. (The nucleus of the egg cell is removed) 3. The nucleus and egg cell are joined using an electric shock to form an embryo 4. The dividing embryo is placed inside a surrogate mother and the pregnancy begins. 5. Birth of clone Who will the clone be genetically identical to: 1. nucleus donor 2. egg cell donor http: //www. science. org. au/nova/043 act. htm 3. surrogate mother

Cloning Summary ?

Do Now 3/6 • Take out your cloning activity. • HW: Research two genetically modified organisms and explain why they are modified. • TEST FRIDAY

Reasons to Clone Organisms 1) Revive endangered or extinct species 2) Reproduce a deceased pet 3) Cloning livestock 4) Drug Production 4) Cloning in medicine 3) Cloning animal models of disease 4) Cloning to make stem cells

Reasons NOT to Clone • Success rate in cloning is quite low • Ethical/Moral issues – “playing God” • Legal issues - how should cloning technologies be regulated • Social issues – impact of cloning technologies on society as a whole.

What color will the baby be? Why? Body Cell (Nucleus) Donor Egg Cell Donor Surrogate Mother Cloned offspring – where the nucleus comes from determines the color

Scientists have cloned sheep but have not yet cloned a human. The best explanation for this situation is that 1. the technology to clone humans has not been explored 2. human reproduction is very different from that of other mammals 3. there are many ethical problems involved in cloning humans 4. cloning humans would take too long

The diagram below represents the process used in 1996 to clone the first mammal, a sheep named Dolly. Which statement concerning Dolly is correct? 1. Gametes from sheep A and sheep B were united to produce Dolly. 2. The chromosome makeup of Dolly is identical to that of sheep A. 3. Both Dolly and sheep C have identical DNA. 4. Dolly contains genes from sheep B and sheep C.

Modern technology could be used to clone pet dogs and cats. The cloned animals would resemble the original pets because 1. the genes of the new animals are different from those of the original pets 2. half of the genetic information of the new animals is the same as that of the original pets 3. the new animals have mutations not found in the original pets 4. the new animals have the same genetic information as the original pets

Cloning Animals – Recipe for Resurrection http: //ngm. nationalgeographic. com/2009/05/mammoths/cloning-interactive

Do Now 3/7 • What does the phrase “The genetic code is universal” mean? • TEST TOMORROW

The Genetic Code is Universal! • All living organisms… – use the same DNA – use the same code book – read their genes the same way (protein synthesis in the ribosomes) Strong evidence for a single origin in evolutionary theory!

Genetic Engineering • Process used to alter the genetic code of an organism Glowing Green Protein ANDi Science 360: Designer Foods Science 360: Genetic Engineering (Insulin)

Why do Scientists Genetically Engineer Organisms? • Medical Reasons – It allows organisms to produce new proteins beneficial for humans • human insulin • human growth hormone (HGH)

How is Genetic Engineering Accomplished? 1. 2. 3. 4. 5. Identify gene Using an enzyme, cut DNA in both organisms Using an enzyme, insert new gene into organism Organism reads gene as if it were its own Organism produces NEW protein NEW TRAIT – New inserted gene causes the organism to produce a new protein (ex: insulin, HGH)

Summary: The Process of Genetic Engineering gene from human cut with enzyme 1. 2. Bacterial plasmid cut with enzyme 3. recombinant DNA 4. recombinant DNA is inserted into a bacteria + 5. Bacteria reproduce (asexual) 6. Extract protein

Restriction Enzymes • Scissor-like enzymes that cut DNA at specific base sequence sites • Restriction enzymes • used by bacteria to cut up DNA of attacking viruses • Ex. Eco. RI, Hind. III, Bam. HI • Cut creates “sticky end”

Real Life Uses of Genetic Engineering • Genetically modified organisms (GMO) – enables organisms to produce new proteins • Protect crops from insects: BT corn – corn produces a toxin that kills corn caterpillar • Extend growing season: fishberries – strawberries contain an anti-freezing gene from flounder • Improve quality of food: golden rice – rice producing vitamin A improves nutritional value Bt Corn: http: //www. teachersdomain. org/asset/tdc 02_vid_btcorn/ Super Salmon: http: //www. teachersdomain. org/asset/tdc 02_vid_salmon/ Article: http: //www. msnbc. msn. com/id/39265727/ns/health-food_safety/

1. What process is represented by the diagram above? 2. What is used to “cut” and “glue” the DNA? 3. Name a specific substance that can be produced by genetic engineering and explain how it is beneficial to humans. 4. What type of reproduction is represented by A?

What Role does DNA Evidence Play in Solving Crimes?

Gel Electrophoresis • Technique used to separate DNA based on size using an electrical field • Uses of Gel Electrophoresis • Forensics • Medical diagnostics • Paternity • Evolutionary relationships

Where do Scientists Find DNA to Compare? • Trace amounts of DNA are found in the following samples: Blood Tissue Semen Urine Hair Teeth Saliva Bone

Humans should be allowed to manipulate the DNA of organisms to make them more useful to humans.

Aim: How are DNA Fingerprints Used to Identify People? Do Now: DNA Regents Questions HW #4: Gel Electrophoresis Biotechnology Test Thursday

Polymerase Chain Reaction (PCR) • Developed by Kary Mullis in 1983 • DNA Amplification - Used to produce large amounts of DNA from trace amounts of DNA Bio. Rad PCR Video: http: //www. youtube. com/watch? NR=1&feature=endscreen&v=_zxr-52 Kw. Ko Bio. Rad GTAC Video: http: //www. youtube. com/watch? v=-b. F 2 Qal. Uj 1 Y&feature=related PCR Virtual Lab: http: //learn. genetics. utah. edu/content/labs/pcr/

Do Now 3/5 • What is the charge of DNA?

Gel Electrophoresis • DNA moves in an electrical field – Why? DNA is Negatively charged – Being negatively charged, DNA moves towards the positive side • The SIZE of a DNA fragment affects how far it travels • Small pieces are Swift and travel farther • Large pieces travel slower & Lag behind DNA – Large “swimming through gel” Small +

Do Now 3/5 • What is the charge of DNA? • TEST Friday

The Steps - Gel Electrophoresis 1) DNA is cut with specific restriction enzymes into different sized fragments. 2)DNA fragments are loaded into wells of the gel. 3)Electric current is passed through the gel making one side + charged and one side – charged. http: //www. youtube. com/watch? v=Fi 63 Vjfhsf. I&safe=active Gel Electrophoresis – CS Harbor Simulation: http: //www. teachersdomain. org/asset/hew 06_int_electroph/

The Steps - Gel Electrophoresis 4) DNA is negatively charged and moves through the gel to the positive side. 5) This electric current causes DNA to separate based on size. – Smaller segments move faster than the larger segments and appear as bands

What Role does DNA Evidence Play in Solving Crimes?

Analyzing Gel Electrophoresis • Ex. Forensics suspects S 1 S 2 S 3 crime scene V sample – DNA Alan Newton Interview – The Innocence Project +

Analyzing Gel Electrophoresis • Ex. Paternity Results