Module 7

Module 7—Molecular Genetics: DNA, RNA, and Protein Synthesis

Read

 

Transgenic organisms other than bacteria and plants have also been created. Consider the following examples:

• goats that produce spider silk in milk for pharmaceutical products
• sheep milk that produces proteins to help treat cystic fibrosis
• cow’s milk that produces an iron transport protein that is added to infant formula
• chickens that can produce human proteins in the whites of their eggs
• mice used in biological experiments
• pigs whose organs can be donated to humans

Once one transgenic organism is produced, scientists endeavour to produce more individuals from that organism. Creating a transgenic organism is a difficult, expensive, and time-consuming task. In order for a herd of transgenic organisms to be created, scientists could wait many generations, or they can use cloning techniques to create “copies” of the transgenic organism. Cloning techniques create hundreds of identical transgenic organisms in just one generation.

 

Cloning an organism uses specific somatic (body) cells from the genetic donor (the animal you want to clone) and then transplants the nuclei of those cells into the egg cells (with nuclei removed) of another organism. The resulting embryos are implanted into a surrogate mother. You may wish to review the cloning process on pages 655 and 656 in your textbook. At this point, you should add the flow chart on page 656 to your course folder.

 

Try This

 

There are many virtual labs on the Internet that simulate the cloning of an organism. Do an Internet search using the keywords “cloning + animation” to find a couple of simulations to try, or complete “Click and Clone.” Work through the simulation to practise and to remember the steps involved in cloning an organism.

 

Read

 

Gene Replacement Therapy

 

Replacing defective genes in humans is a new way to prevent and/or treat genetic disorders. This new therapy is called gene replacement therapy. This type of therapy attacks the cause of the disorder instead of treating the symptoms. Most of the research trials have concentrated on treating somatic cells (somatic gene therapy). This type of treatment can only improve the health of the individual patient.

 

A more controversial therapy, germ-line therapy, modifies the genetic information in the egg and sperm cells and could eliminate the disorder in offspring. Currently, germ-line therapy is banned in Canada. Read more about gene therapy, the use of DNA vectors to alter the genetic material in humans, and the controversy surrounding this new form of treatment under “Treating Human Genetic Disorders” on pages 660 and 661 of your textbook.

 

You may choose to review some of the diagnostic procedures, such as amniocentesis and genetic probes, that you have learned in this course by reading “The Diagnosis and Treatment of Genetic Disorders” on pages 658 to 659 of your textbook.

 

Module 7: Lesson 5 Assignment—Part 3

 

Retrieve the copy of the Module 7: Lesson 5 Assignment that you saved to your computer earlier in this lesson. Complete Part 3, which is based on the concepts you have learned in this lesson. Save your completed assignment in your course folder. You will receive instructions later in this lesson about when to submit your assignment to your teacher.

 

Discuss

 

Complete either D 1 or D 2.

 

As you do the following research, remember that technologies, their methods and uses, the controversy, and the societal issues that can surround them are often part of the open-response essay question on your Diploma Exam.

 

D 2. Review “Ownership of Genetic Information” on pages 653 and 654 of your textbook. Think about the following questions and create a discussion posting stating your opinions. Check out some of the other postings by your classmates and respond to at least two of the postings.

 

Who owns the genetic information of the transgenic organisms? Should companies have the right to sell DNA information to other companies without the permission of the people who provided the samples? Should companies that use DNA in medical research be required to share the results of their work with the individuals whose genetic information was used? What are the advantages and disadvantages of companies patenting genes like “Roundup-Ready”?

 

D 3. Many controversial sciences and technologies have been discussed during this lesson. Choose one example or topic that stood out for you more than all of the others. Do some extra reading on the Internet about this topic. How did this extra information affect your opinion? Create a discussion posting about the example or topic and state your opinion OR present a few interesting facts that you found during your extra research. Check out some of the other postings by your classmates, and respond to at least two of the postings.

 

Reflect and Connect

 

Think about what you have learned in this lesson. In Reflect on the Big Picture, use your knowledge to outline the steps that you would perform to have a gene inserted into or removed from your DNA.

 

You may want to discuss your work with your peers and teacher in the discussion area.

 

Reflect on the Big Picture

Imagine that you could have any gene inserted into your DNA. What would you choose? If you could get rid of any gene or genes, what would you pick? Would this help you become a superhero? What would be the societal, ethical, and medical issues related to the insertion of this gene? 

 

Self-Check

 

SC 3. Complete the Self-Check activity Transgenic Organisms. Check your answers as you complete the activity.

 

Module 7: Lesson 5 Assignment

 

Submit your completed Module 7: Lesson 5 Assignment to your teacher for assessment.

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