Explorers of DNA   

DNA Pioneer Webquest 

Introduction                         Task                          Process                      Reflection                    Conclusion              Sources  

Introduction:

This webquest is going to take us on an adventure along with the Explorers of DNA! We are going to study pioneers in DNA research and what they have contributed to the field of biology. You will travel to various sites to collect information which will then be used to answer questions regarding the pioneer and their DNA discoveries!

Task:

Students will travel to various websites to collect information on pioneers in DNA research such as Mendel, Watson, Crick, and the researchers involved in the Human Genome Project. Students will then answer questions relating to each pioneer and their DNA discoveries. This webquest is based on National Science Education Standard C for grades 9-12:   

• In all organisms, the instructions for specifying the characteristics of the organism are carried in DNA, a large polymer formed from subunits of four kinds (A, G, C, and T). The chemical and structural properties of DNA explain how the genetic information that underlies heredity is both encoded in genes (as a string of molecular "letters") and replicated (by a templating mechanism). Each DNA molecule in a cell forms a single chromosome. [See Content Standard B (grades 9-12)]
• Most of the cells in a human contain two copies of each of 22 different chromosomes. In addition, there is a pair of chromosomes that determines sex: a female contains two X chromosomes and a male contains one X and one Y chromosome. Transmission of genetic information to offspring occurs through egg and sperm cells that contain only one representative from each chromosome pair. An egg and a sperm unite to form a new individual. The fact that the human body is formed from cells that contain two copies of each chromosome--and therefore two copies of each gene--explains many features of human heredity, such as how variations that are hidden in one generation can be expressed in the next.

Process:

You may choose to work in teams or individually. By clicking on the pictures above, you will begin your exploration of the pioneers of DNA. Visit each site to answer the following questions:

1.  In what year did Mendel find that traits were linked to genes?

2.  Mendel found that visible traits were called _________.

3.  Mendel used what vegetable in his genetic research?

4. Two __________  make up the genotype.

5. Watson and Crick are responsible for finding the structure of what molecule that they called "the secret of life?"

6. Watson and Crick found that DNA is a ________ _______ shape and carries genetic information.

7. Watson was studying the bases that make up DNA when he discovered the helix relationship. What are the bases that make up DNA? 

8. In what scientific journal did Watson and Crick publish their findings?

9. When did the Human Genome Project begin?

10. What is the goal of the Human Genome Project?

11. What are three experimental organisms that the Human Genome Project is working to sequence?

12. Looking at the timeline in 1999, what was the first human chromosome  that was sequenced?

13. What did the sequence of chromosome 22 provide for the researchers?

14. List two things researchers see as future impacts of the Human Genome Project (under The Future in the timeline).

15. Using the genetic dictionary link, define the following words we have not discussed in class yet:                             

                ►Phenotype        ► Allele                  ► Genome             

                ►Genotype          ► Chromosome   ► DNA (what does it stand for? )

Reflection (Guidance):

• Purpose: Students will use the internet to find the answers to the 15 questions listed above. Through answering these questions, students will discover the beginnings of DNA research and the researchers involved. Furthermore, students have an opportunity to define terms that are not familiar to them.
• Preceding and ensuing instruction: Prior to this exercise, the class will discuss the importance of DNA as the basic genetic material of all living matter. Students will be given basic information regarding the function of DNA in their bodies. After this exercise, students will begin an in-depth study of DNA to include the 4 bases of DNA, the double helix model, DNA replication, chromosomes, human heredity, and DNA mutations.
• How this exercise will assist in learning: This exercise gives the students an opportunity to view the research that has been competed regarding DNA. Furthermore, students will learn about on-going genetic research and the impact it has on society  through studying the Human Genome Project.
• How this exercise may be improved or expanded: This exercise could include word games to build vocabulary, a basic labeling exercise of Watson and Crick's double helix, and a sample Punnett Square to illustrate basic Mendelian Genetics.

Conclusion

This lesson provides students with basic information regarding the pioneers of genetic research such as Mendel, Watson and Crick, and the researchers involved in the Human Genome Project. In addition, students are introduced to terms previously not discussed in class such as phenotype, genotype, allele, genome, chromosome, and DNA.

Answer Key:

1. 1865
2. phenotypes
3. peas
4. alleles
5. DNA
6. double helix
7. adenine, cytosine, guanine, and thymine
8. Nature
9. 1991
10. to sequence the human genome-all DNA
11. yeast, mouse, nematode worm
12. Chromosome 22
13. The  first look at an entire chromosome's organization
14. 1. Causes of more diseases will be understood.  2. New drugs will be developed. 3. Our knowledge of biology will increase.
15. Phenotype:  For the appearance of an organism with respect to a particular character or group of characters (physical, biochemical, and physiologic).

    Genotype:  For  the hereditary constitution of an individual, or of particular nuclei within its cells.

    Allele: Two or more alternative forms of a gene resulting in different gene products and, thus, different phenotypes.

    Genome:  The self-replicating genetic structures of cells containing the cellular DNA that bears in its nucleotide sequence the linear array of genes.

    Chromosome:  The self-replicating genetic structures of cells containing the cellular DNA that bears in its nucleotide sequence the linear array of genes.

    DNA (what does it stand for?): Deoxyribonucleic acid (DNA).

Sources:

Cold Spring Harbor Laboratory. (2002). DNA from the beginning. Retrieved March 22, 2004, from  http://www.dnaftb.org/dnaftb/2/concept/index.html

National Academies of Sciences. (1995). National Science Education Standards. Retrieved March 26, 2004,  from http://www.nap.edu/readingroom/books/nses/html/6e.html#ls

National Human Genome Research Institute. (2004). The human genome project. Retrieved March 22, 2004, from http://www.genome.gov/Pages/EducationKit/online.htm

Schlindwein B. (1999). Hypermedia glossary of genetic terms. Retrieved March 26, 2004, from http://hal.weihenstephan.de/genglos/asp/genreq.asp?list=1

Tamarin, R. H. (1999). Principles of genetics. Boston: McGraw Hill.

Time, Inc. (2003). The Time 100 scientists and thinkers; Francis Crick and James Watson. Retrieved March 22, 2004, from http://www.time.com/time/time100/scientist/profile/watsoncrick.html