Activity Description
Prior to the DNA isolation, students will participate in the DNA dance. At this point
DNA structure will be reviewed. This includes 5’ and 3’ end, sugar, phosphate group, and nitrogen containing bases. Students will then be broken into small groups. The students will then choose from what material they will extract their DNA from. Their choices will include the following but not limited too: strawberries, banana, onion, yeast, chicken liver, beef liver, and animal tissue. Students will have a control group where they follow the procedure as described and then vary one of the variables and determine what type of effect this will have on their results. Upon completion, students will white-board their results to share with the class.
Class
This activity will be incorporated into 10 th
grade biology. DNA structure is covered in our nucleic acids and protein synthesis unit. We currently do this activity in class but it has been limited to only observing the DNA and understanding why we used certain materials. We have currently made our physical science course an integrated science course covering chemistry, physics, and now an introduction to biology. This has allowed for a little more room in the biology curriculum for the upcoming school year.
This activity will take 3 1/2 days – 4 days (46 minute periods). The DNA dance and lab modification will be on day 1. DNA isolation will be day two. Day 3 will include preparation of white-boards followed by short presentation on what they did and what their results where.
Outline
Day 1

Review basic DNA structure (sugar, phosphate group, base pairing, hydrogen bonds, 5’ and 3’, and DNA location

Assign students as one of the four nitrogen containing bases
 Students perform the dance making note of the 5’ and 3’ end

Possible extension could be the addition of the helicase and polymerase

Students get into their small groups and determine what substance they will be using and what variable they will be manipulating

At the end of the period, review what was done
Day 2

Review from day 1

Short quiz on DNA dance

Students get into their small groups and begin working on their isolation

Upon completion, students begin analyzing their data

At the end of the period, review any questions students may have

Day 3

Students begin preparing white-boards

White-boards should include the following: title, DNA used, variable manipulated, results from control and experimental, initial hypothesis, and results
(students should have a rough draft prepared prior to class. This will help reduce the amount of time needed).

Students share with the class what was done, rationale for their variable manipulation, and results.
Day 4

Wrap up

Quiz
Background
Below is the outline we follow for this unit. This investigation will take place after section II.
Concepts-Outline
I. History of discovery of DNA as genetic code
Griffith’s discovery of transformation factor
Avery’s proof that DNA is transformation factor
Hershey and Chase’s bacteriophage experiment
Chargaff’s rules
Franklin’s DNA X rays
Watson and Crick’s discovery of DNA’s structure
II. DNA/RNA structure
Nucleotide structure- include 3’ and 5’ carbons of deoxyribose
Double helix structure- anti-parallel strands
Hydrogen boding between pyrimidine and purine nitrogen bases
Base pairing rules
III. Replication
Messelson and Stahl’s discover of semi-conservative DNA replication
Replication bubble and replication fork
Identification of and differences in replication of leading and lagging strand
Role of various enzymes in replication process
DNA polymerase also “proofreads” the replicated DNA
Telomeres and telomerase
IV. Transcription
Transcription starts at promoter region and ends at terminator
RNA polymerase builds RNA from 3’ to 5’
Primary mRNA transcript is modified before leaving nucleus
Introns and exons

V. Translation
Khorana’s discovery of mRNA to amino acid translation code tRNA structure and role in translation rRNA and ribosomal structure
Initiation, elongation, and termination processes
Role of start and stop codons
Post-translational modification of polypeptides

Background information can be found in any high school level biology text or AP
Biology Text. Clintonville High School Science Department is textbook free. We tend to go into more detail so some of the information could be eliminated from your unit.
Exercises to be Included
The DNA dance is an activity that will help students better understand the idea of DNA and how it is arranged. This will give students who learn better by “doing” an opportunity to understand the concepts need for structure of the DNA double helix.
The DNA isolation lab will allow students to individually extract DNA from a given substance. They will also learn about DNA solubility. Please use your binders for procedure and instruction for extraction of the various substances.
Special Needs
For the dance and isolation, there are no modifications. Quiz and test material can be adjusted for special need students as needed. Students who may be allergic to certain chemicals will either observe from a distance or use material that will allow that student or students to participate in the lab.
References

DNA dance: www.biotech.wisc.edu/outreach/dnadance.html

Wheat Germ: http://gslc.genetics.utah.edu/units/activities/wheatgerm/

Onion: http://www.biotech.iastate.edu/publications/lab_protocols/DNA_Extraction_Onion.pdf

Liver: http://educ.queensu.ca/%7Escience/main/concept/biol/b05/B05LACG5.htm

Yeast: http://www.accessexcellence.org/AE/ATG/data/released/0508-LanaHayes/yeast1.html
 https://biotechforteachers.wikispaces.com/space/showimage/DNA+spooling_instructor.pdf
 Lab reports: Supplied by the University of Wisconsin-River Falls 2007

Many chemicals can be purchased at local stores or ordered from your chemical distributor for your school district.
Evaluation/Assessment Method
Students will be given a short quiz on day 2. This will cover questions regarding to basic
DNA structure and lab procedure. For each class, questions will vary. When the quiz is completed, a short discussion will follow.

White-boarding will be graded according to the rubric designed by the teacher according to district and department expectations. The rubric will be handed out prior to the activity.

The following items could be found on the grading rubric:
Correctly written hypothesis
Identify the control
Identify the experimental
What variable what manipulated and why?
Neatness/organization
Explanation of results
Some example lab report questions are included at the end of this project. Questions were used from the lab reports produced by teachers of UW-RF for the 2007 Biotechnology for
Teachers Course
The final quiz will include questions covering why certain materials were used, DNA structure, DNA dance and procedure. It is up to the instructor to determine what they feel students should understand once completing the activity/lab.

Some example lab questions:
1.
What is the purpose of the alcohol?
2.
Why is it necessary to obtain large quantities of DNA?
3.
What is the purpose of the liquid detergent?
4.
Why was it necessary to smash the material before extracting the DNA?
5.
Why was it necessary to use the cheesecloth?
6.
What is the importance of DNA having a charge? What is the charge of DNA?
7.
Why must you keep the ethanol on ice prior to using it?
8.
If you obtain strands of DNA what is one possible explanation for your results?
9.
Why is it possible to see the DNA?
*Each question can be modified to be short answer or multiple choice based upon the teacher requirements.
Alignment with Standards
The following standards (Wisconsin State Standards) will be covered in this activity:
Standard B: Nature of Science

B.12.4
Standard C: Science Inquiry

C.12.1, C.12.2, C.12.3, C.12.5, C.12.6
Standard F: Life and Environmental Science

F.12.3
Standard G: Science Application

G.8.2, G.12.4

Examples of possible Lab Report
Lab Report – DNA isolation
Due Tuesday 7/10/07
Name
1. Describe your experimental design. What was your source of DNA? What variable did you alter? What was your experimental hypothesis?
(Attach your protocol and materials list.)
2. What was the result of your experiment? How did you measure the quantity and/or quality of DNA isolated?
3. What would you do differently if you were to repeat this experiment?

Lab Report – DNA Isolation
Due Wed. 7/9
1. Which tissue did you use as a source of DNA?
Name
2. What variable did you test? How did you test it?
3. How did you determine which protocol produced the "best" DNA isolation?
4. Summarize the results of your DNA isolation and the effect of your variable on the result.
5. Describe the role of each of the following reagents: detergent, meat tenderizer, alcohol
6. If you were to repeat this activity, what would you do different to try and improve the result?
7. Briefly describe how you could use DNA isolation as an open-ended lab activity in your class.