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What do you think about eating genetically modified foods?

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Presentation on theme: "What do you think about eating genetically modified foods?"— Presentation transcript:

1 What do you think about eating genetically modified foods?

2 Start-up for 2/26/14 Watch the following short video titled "Classical versus transgenic Breeding".
In your Start-up section, complete a quick-write addressing the following questions: Why are transgenic organisms good? Why are they bad? Are you in favor or against using transgenic organisms in our food supply? Why or why not? Do you think it is necessary for us to use transgenic organisms? You have three minutes to complete your quick-write.

3 Biology Chapter 13 Sections 3 and 4 – Pages 327-333
Objectives: Students will A) Identify the role of genetic engineering. B) Define recombinant DNA. C) Summarize how transformation occurs. D) Summarize how transformation creates transgenic organisms. E) Summarize how genetic engineering creates novel biomedical and agricultural products. F) Summarize the 7 steps to a successful clone.

4 A) Identify the role of genetic engineering. B) Define recombinant DNA.
Genetic Engineers can alter the DNA code of living organisms. Bacteria are often used in biotechnology as they have plasmids Plasmid = circular piece of DNA, exists apart from the chromosome and replicates on its own.

5 Recombinant DNA B) Define recombinant DNA.
Combination of a piece of DNA of one organism with the DNA of another organism. Host DNA is often bacteria such as E coli. Why? Bacteria reproduce quickly making millions of copies of the recombinant gene.

6 Recombinant Bacteria B) Define recombinant DNA.
Cut the required gene (i.e. insulin) from DNA using “restriction enzymes”. Remove bacterial DNA (plasmid). Cut the plasmid with same “restriction enzymes”. Mix human gene with plasmid. Because they were cut with the same enzyme, the cut ends of the plasmid and human gene match. Often called ‘sticky ends’. Enzyme DNA ligase is used to stick the ends together = recombinant DNA.

7 Re-Introducing the Plasmid Back - TRANSFORMATION
C) Summarize how transformation occurs. Re-Introducing the Plasmid Back - TRANSFORMATION Plasmid containing recombinant DNA needs to be reinserted into the bacteria so they can multiply and make more of the gene. Done by combining them in a test tube with CaCl2. Calcium ions make the membranes of the bacteria porous = many holes. Allows plasmids to move into the bacterial cells. Not all bacteria will take up a plasmid so monitoring must happen.

8 How do we know which bacteria have the gene?
C) Summarize how transformation occurs. How do we know which bacteria have the gene? Must isolate host bacteria containing the spliced gene. We want the recombinant DNA. How? By having a gene on the same plasmid that resists an antibiotic, the other bacteria will die when placed in a medium containing the antibiotic. The bacteria containing the resistance to the antibiotic will survive. Antibiotic resistance gene used to ID recombinant cells = Genetic Marker

9 What is used to insert foreign DNA?
ANIMATION – RECOMBINANT DNA Answer the following questions while watching the animation. What is used to insert foreign DNA? What is used to cleave (cut) the foreign DNA and plasmid? Why is an antibiotic resistance gene also placed in the recombinant plasmid? How are many copies of the recombinant DNA created?

10 How to Create a Transgenic Plant or Animal
D) Summarize how transformation creates transgenic organisms. How to Create a Transgenic Plant or Animal 1.Create recombinant bacteria with desired gene. 2. Allow the bacteria to “infect" the plant cells. 3. Desired gene is inserted into plant chromosomes. Recombinant DNA is added to an egg cell, the only time we can modify.

11 Transformation creates transgenic organisms.
E) Summarize how genetic engineering creates novel biomedical and agricultural products. Transformation creates transgenic organisms. TRANSGENIC ORGANISMS Mice – used to study human immune system Chickens – more resistant to infections Plants – pest resistance Bacteria to create medication = insulin for diabetics, dissolving blood clots of heart attack patients, human growth hormone for those lacking it Pigs and mice – glow in the dark, firefly and jellyfish gene Goats – creating milk with blood clotting agent Contains human gene that codes for a blood clotting agent. It is harvested in the goat’s milk.

12 F) Summarize the 7 steps to a successful clone.

13 F) Summarize the 7 steps to a successful clone.

14 Understanding Check What is recombinant DNA?
Why is transformation related to transgenic organisms? Identify 2 examples of novel biomedical or agricultural products created from genetic engineering. What is a clone? Why is genetic engineering useful?


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