Learn from home--genetic engineering

Genetic engineering:




Since all life uses the same code (A,T,C,&G), if we change the order of those bases, we can control life in ways never before.


Engineering other organisms is not new.  We have been doing this for thousands of years through selective breeding practices.

Selective breeding: choosing which organisms will reproduce.  

     This would be like Mendel did with his pea plants or most farmers do with their livestock.  If you want cows that make a lot of milk, you only keep the offspring of the most productive cows.  Over time, this selective breeding for traits engineers the organisms.

Inbreeding is when you breed the traits you want regardless of how related the parents are.  For example, if you have a litter of dogs with green spots and want to make a green spotted breed, you need to inbreed these siblings for a few generations.  That is how many breeds have been made.

Crossbreeding is when you cross two animals with different traits searching for a mix.  For example, if you have a cow that produces lots of milk and another that produces creamy milk, you may crossbreed them to (hopefully) get one that makes lots of creamy milk.  If you do, it is time for inbreeding.


But in relatively recent years, humans have figured out how to control this more precisely.  They can put genes from one organism into another organism (cross species even!).  They can alter genes.  They can select genes.  


How this is done depends on what you hope to do, but generally the steps are:

1. identify the desired gene.  It must be something that occurs naturally in some organism.

2. cut the desired gene out of that DNA.  Hopefully we only cut out the one stretch that we want.  

3. cut the new organisms DNA with the same restiction enzyme.  This makes both ends cut identically.

4. combine the two sections of DNA.  Hopefully they combine as we plan.

5. insert this recombinant DNA into a zygote.  Why must it be a zygote?

6. check organisms for the desired trait.  Sometimes they add markers to make this step easier.


There are too many topics to cover and they are growing daily.  Instead, I want each of you to pick one topic.  If nothing in genetic engineering interests you, at least choose a topic of biotechnology (the interplay between life and technology).  You are going to research that topic and write your third and final research paper on it.  This is a bioethics paper.  That means that I want you to research how it is done, the reasons in favor of doing it, and the reasons against doing it.  Then you will conclude with your opinion of where you draw the line regarding your topic.  Here is the link to the paper.

Some topic ideas:

gene therapy - trying to fix genetic disorders


     - food to be easier to grow (herbacide, pest, disease, or frost resistant, harsher growing conditions, etc.)
     - food to be more nutritious (golden rice, vitamin chocolate, etc.)
     - pets to be better pets (glowfish, hypoallergeneic cats, etc.)
     - bacterial minions (drug producers, oil eaters, gas makers, etc.)


     - therapudic
     - bringing back extinct species
     - whole organisms

     - human

Transgenic organs - putting organs in a different species

DNA fingerprinting - identifying people based on their DNA

DNA chips - Identifying genetic "disorders" by screening


     - choosing the traits of your offspring

     -choosing the sex of your offspring