Download DNA Webquest - Fredericksburg City Schools

Name ______________________________
Date ___________________
Block _________
DNA Webquest
Part I. History of DNA
Go to: http://www.dnaftb.org/dnaftb/1/concept/index.html
Read the text and answer the following questions.
1. What have people wondered since the beginning of human history?
2. Who discovered that individual traits are passed on from one generation to the next? In what year?
On the menu at the right click on Molecules of Genetics tab and then number 19 “The DNA molecule is
shaped like a twisted ladder”, then click on the Animation tab. (click through the animation and answer the
following questions).
1. What makes up a nucleotide?
2. How could DNA be an “intelligent molecule” (carry hereditary information)?
3. What was Erwin Chargaff’s contribution to the DNA puzzle?
4. What important tool did Linus Pauling use to determine the structure (shape) of proteins?
5. How was this tool used to help discover the shape of DNA?
6. Name the two scientists that made the x-ray diffraction patterns that Watson & Crick used?
7. The distinctive “X” meant the DNA had what pattern?
On the menu at the right click on Molecules of Genetics tab and then number 27, “Mutations are changes in
genetic information”.
Read the text and answer the following questions.
1. DNA differences results from a mutation of what 3 possibilities?
2. In humans, where do the majority of mutations occur?
On the menu at the right click on Molecules of Genetics tab and then number 28, “Some types of mutations
are automatically repaired”.
Read the text and answer the following questions.
1. The notion that DNA could be damaged and then repaired came from what? Give the example.
2. What have the investigations of organisms from bacteria to humans uncovered?
On the menu at the right click on Genetic Organization and Control tab and then number 29, “DNA is
packaged in a chromosome.
Read the text and answer the following questions.
1. In the late 1800’s what did scientist believe about DNA?
2. What did Avery and Hershey prove?
3. What was shown to be true in the 1960’s and 70’s?
On the menu at the right click on Genetic Organization and Control tab and then number 35, “DNA responds
to signals from outside the cell.”
Read the text and answer the following questions.
1. What do growth and development require?
2. What do hormones do in the body?
3. What happens to a cell when stimulated by a hormone?
Go to the DNAi website: http://www.dnai.org/a/index.html
Click on “Finding the Structure” at the bottom of the page, then click on “putting it together” at the top of the
new page. Click on the picture next to “base pairing interactive”. Go through the steps to determine how the
nitrogen bases pair, and how the sugar phosphate backbone is formed. Draw your results in the box below using
the diagram at the end of the module.
Click on
the red arrow to move to part 2 of the puzzle.
Assemble the fragment of DNA. Draw your results in the box below using the diagram at the end of the module.
Click on
the red arrow to watch the DNA molecule reveal its 3D structure.