Natalie DiPaolo                                                                                                                                        Return to Biology Menu

Saunders Trades and Technical HS

Grade 9

Living Environment

Summer 2001

 

                                                           The Human Genome

  

Learning Objective(s):

Students will read and discuss the article “Genome’s Riddle: Few Genes, Much Complexity” by Nicholas Wade (New York Times, Feb. 13, 2001). They will use the article as an introduction to a trip to the Museum of Natural History’s “The Genomic Revolution” exhibit. They will complete the experience with a laboratory exercise on DNA Electrophoresis and Forensic Science from Carolina Biological.

 Materials:

New York Times Article “Genome’s Riddle: Few Genes, Much Complexity” by Nicholas Wade (New York Times, Feb. 13, 2001)

Reference Materials on Genetics

Tickets to the exhibit

Computers with Internet access

 

Activ ity:

Part I:

a.       Read the above-mentioned article in groups of four.

b.      Answer a list of questions related to the article.

  1. What is the main point of the article/
  2. What did you learn?
  3. Do you think that the human genome project is worthwhile? What implications do you think it will have on the future of genetic research?
  4. Why would pharmaceutical companies be interested in the discovery of new human genes?
  5. List new vocabulary words

c. Class discussion on article and questions.

d. Assign genetic terms (DNA and RNA, gene and chromosome, meiosis and mitosis, exons and introns) to the various groups and have them use the Internet and other references to research the terms. They must create a chapter of a children’s book explaining the terms. Each group’s work will be put together to create a book.

 

Part II: Trip to AMNH Exhibit

Students will be able to visit the DNA learning lab where they will isolate and sequence their own DNA with the use of a centrifuge, PCR thermal cycler and a DNA sequencer.

   

Referenced Science Standards:

S2- Demonstrates an understanding of the cell

S4a-Demonstrates an understanding of big unifying concepts

S5f-works individually and in teams to collect and share data and ideas

S6a-Uses technology and tools to measure objects, organisms, and phenomena

S8b-Demonstrates scientific competence by completing fieldwork.

            

Part III: Lab on DNA Electrophoresis and Forensic Science

                                                       

                                               DNA Electrophoresis and Forensics

Objectives: 

Students will be able to:

  1. Perform a gel electrophoresis of DNA and analyze the bands.
  2. Examine evidence and conclude the identity of a suspect in a simulated crime scene using the evidence provided.

 

Materials:    Can be purchased from Carolina Biological.

Agarose gel

Gel electrophoresis chamber

Power supply

TBE electrophoresis buffer

Comb

Pipettes

Methylene blue

Gloves

Distilled water

White light source

DNA samples (victim, suspect 1, suspect 2)

 

Overview:  DNA isolation from blood, hair, skin cells, or other genetic evidence left at the scene of a crime can be compared with the DNA of a criminal suspect to determine guilt or innocence. This is due to the fact that every person has a different sequence. Scientists use a small number of sequences of DNA that are known to vary among individuals, and analyze those to get a possibility of a match.  DNA is isolated, cut using restriction enzymes and sorted by size by gel electrophoresis. DNA is placed in a gel and an electrical charge is applied to the gel. The positive charge is at the top and the negative charge is at the bottom. Because DNA has a slightly negative charge, the pieces of DNA will be attracted to the bottom. The smaller pieces move more quickly towards the bottom than the larger pieces. The DNA can then be analyzed.

 

Procedures: The teacher will create a crime scene scenario and students will be given information to assist them in determining how the crime was committed and who might be suspect. Students will work in groups of four. The teacher will prepare any needed material to expedite time. Each group will obtain their gel chambers, agarose, and samples.

 

Students will:

Day 1

1. Pour agarose gel into the gel electrophoresis chamber.

2. Place a comb in the agarose and allow it to harden.

3. When the agarose is solid, cover it with TBE electrophoresis buffer and remove the

comb.

4. In the first well, pipette DNA from the victim. Using a clean pipette each time, place. DNA from suspect 1 into the second well and DNA from suspect 2 into the third well.

5. Put lid on gel chamber and plug into the power supply.  Allow the fragments to separate.

Day 2

1. Visualize the bands by placing the gel carefully in methylene blue stain. Let the stain set for 30 minutes, remove and place the gel in distilled water to destain.

2. Set the gel on the white light source and compare the bands.

3. Measure and draw the bands exactly as they appear on the gel.

4. Determine which suspect was at the scene of the crime and write a one page report supporting your suspicion.

  

Referenced Science Standards

S2-Demonstrates a knowledge of life science concepts

S4a-Demonstrates an understanding of big unifying concepts

S5f-Works individually and in teams to collect and share data and ideas

S6a-Uses technology and tools to measure objects, organisms, and phenomena

S7b-Argues from evidence