Activities
We will begin with a study DNA from a cellular level. Students will review the general structure of cells, the general function of major organelles, and the location of genetic material in the cell. Students will study chromosomes, watch simplistic videos of mitosis, and understand that the origin of life is debatably genetic. After reviewing Ridley's book analogy (see paragraph 10 above), students will be asked to create an advertisement poster for the "book" of DNA. Then, to further prove their ability to express the progression from chromosome to base pair, students will create their own analogies and make an artistic representation of their analogy to be displayed at the end of our unit in a gallery walk. We will then move into base pairings, restriction enzymes, polymerase, and ligase.
In an inquiry activity designed to demonstrate an understanding of restriction enzymes students will be given a long strand of double stranded DNA base pairs. Then they will be given three restriction enzyme codes. Students will cut their DNA strands at the coded restriction enzyme locations. Once their DNA has been cut into pieces they will trade with a designated partner who received different restriction enzymes. With their partner's pieces they are to reconstruct the original DNA strand. Then they will have to justify their recreation. Why are the pieces where they are? How do you know you've reconstructed it correctly? Are there any other possible arrangements? Why or why not?
We will then look at the uniqueness (or non-uniqueness) of human DNA. Comparing human DNA to DNA of different species will allow for the discovery of a common platform for all biotic factors on Earth. We will extract DNA from strawberries, green split peas, and chicken liver. All are plentiful in DNA and easy to extract and visualize (see Appendix A). We will compare our findings and make generalizations about the three samples. Then students will be given a research project to find the base pair sequence of first chromosome of humans and compare it to the first chromosome of different animals (chicken, mouse, dog, and chimpanzees). Again the focus will be the comparison of two different species' DNA sequences; students should find that they are actually quite similar. Students will then find the percentage of similarity and make some generalizations about all species.
After we've discovered that most organisms derive from a similar DNA platform we will begin to focus on the idea of genetic manipulation and building the perfect pet. We will study pedigrees of the current Westminster Dog champions and track histories of hip dysplasia and other common diseases. We will discuss and contemplate the ability to pinpoint single (and multiple) gene causing diseases and derive an understanding of the trade-offs and philosophical arguments made about pinpointing disease causing genes. We will have several activities related to selective breeding. Students will have the opportunity to selectively breed their own animal in an online game, choosing specific traits and characteristics to build the "perfect" pet. Through these discussions and activities students will be able to articulate how selective breeding works and the advantages and disadvantages of using this method to breed favored traits. With both an understanding of genetic inheritance and selective breeding students will then really begin to unravel the science behind genetic engineering.
Next we will look at the history of crop cultivation and its recent technological evolution. We will be visiting a genetic engineering lab where students will have the opportunity to view and participate in hands on activities related to genetic modification including PCR. Students will participate in a teacher designed game (see instructions in Appendix A) where they are farm owners, some organic non-GMO, some organic GMO, and some nonorganic GMO. Similar to the game of Monopoly, students in small groups will have to strategize for their farms' success despite natural and human created obstacles. The game can easily be modified to fit higher or lower students by changing the math calculations, initial money allocations and acreage.
Finally, we will look at the controversy of genetically modifying our food supply. We will research commonly modified food then go on an ingredient hunt in our own homes making a mess of the kitchen but separating all the food in the pantry into modified and non-modified quarters. We will study California's proposition 37 which would have demanded a labeling of all genetically modified foods. Afterwards we'll perform some simple taste tests of modified foods. Then students will research the processes, potential dangers, and inconsistencies to genetically modified foods. Although pertinent articles will be included throughout the unit, the bulk of the reading standards will be accomplished here. As the unit's finale students will write their congressional leaders to convince them to continue research into genetic modification or stop production. Students will need to include a complete explanation of the DNA molecule and the history of cultivation as well as their opinions supported by evidence and research.
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