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Lab Biology
Name__________________________
Webquest: Learn about DNA
Go to "A Science Odyssey: DNA Workshop" Web site. Read the introduction and answer
Questions 1 and 2 below.
1. In which year were nucleic acids discovered?
a) 1869
b) 1940
c) 1952
2. Name the scientists who proposed an accurate model of DNA in 1952:
Click on the "DNA Workshop Activity" title. When the screen finishes loading, click on
"DNA Replication" and answer the following questions.
3. Where in the cell does DNA replication occur?
a) cytoplasm
b) nucleolus
c) nucleus
d) ribosomes
Follow the directions on the screen and answer the following questions.
4. DNA is held into tight spools by:
a) carbohydrates
b) proteins
c) nucleotides
5. Describe the role of enzymes in the "unzipping" procedure.
6. List the complementary base pairs that match up to create the rungs of the DNA ladder.
Return to "A Science Odyssey: DNA Workshop" and scroll down the page to where you
can learn more about DNA Replication. Click on "DNA Replication" and answer the
following questions.
7. Draw a single strand of DNA and label the model of DNA, using the following terms:
5-carbon sugar (deoxyribose)
nitrogenous base pair
phosphate
Circle a "nucleotide" on the model.
8. Describe the steps of DNA replication in your own words by listing the three major steps.
Step 1:
Step 2:
Step 3:
9. How error-free is DNA replication?
Lab Biology
Name__________________________
Webquest: Make a Protein using DNA
Go to the "A Science Odyssey: DNA Workshop." Click on the "DNA Workshop Activity"
title. When the screen finishes loading, click on "Protein Synthesis" and answer the
following questions.
1. Look at the cell model. Where is the DNA found that unzips when a protein is to be made?
a) cytoplasm
b) nucleolus
c) nucleus
d) ribosomes
Follow the directions on the screen and answer the following questions.
2. List the RNA bases that pair up with the DNA nucleotides on the unzipped molecule during
Transcription.
DNA base
A
RNA base
T
DNA base
C
RNA base
G
3. How many nucleotides might be in a "real" mRNA molecule? _____________
4. The "m" in mRNA stands for: ______________________________________
5. Once constructed, the mRNA leaves the cell's nucleus and travels to the:
a) cytoplasm
b) nucleolus
c) nucleus
d) ribosomes
6. Find the single strand of mRNA attached to the ribosome. The mRNA bases are grouped into sets
of three, which are called:
a) amino acids
b) anticodons
c) codons
d) genes
7. tRNA molecules contain three exposed bases which are complementary to the codons of mRNA.
These three bases on tRNA are called:
a) amino acids
b) anticodons
c) codons
d) genes
8. The
a)
b)
c)
d)
building blocks of a protein are attached to tRNA a molecules. These are specific:
amino acids
anticodons
codons
genes
9. Complete the table after you've matched the tRNA molecules onto the mRNA template.
mRNA codon
AUG
GGC
UCC
tRNA anticodon
______________
______________
______________
amino acid
______________
______________
______________
10. Describe what happens to the tRNA after it delivers its amino acid to the mRNA template.
11. How many amino acids are found in a typical protein? __________
12. Protein synthesis is completed when
a) a special stop codon is reached
b) the cell has no more amino acids available
c) the ribosomes disintegrate
d) the tRNA anticodons no longer match the mRNA codons
Return to "A Science Odyssey: DNA Workshop" and scroll down the page to where you
can learn more about Protein Synthesis. Click on "Protein Synthesis" and answer the
following questions.
13. As a result of its job in controlling protein synthesis, how is DNA able to direct all of the cell's
activities?
14. How many DNA nucleotides are needed to code out protein that contains 400 amino acids? Show
your calculation here:
15. How long will it take the cell to construct that protein?
Lab Biology
Name__________________________
Webquest: Solve a Crime using DNA
Go to the NOVA's "The Killer's Trail" Web site to read about a crime and be involved in
finding the perpetrator. Choose “Create a Fingerprint”.
1. Who is the victim of the crime described in "It takes A Lickin'..."?
2. What crime was committed?
3. What substance is available at the crime scene from which a DNA fingerprint can be made?
Continue with Part 2: Click on "DNA Fingerprinting in the NOVA lab." Follow the
directions to create a DNA fingerprint. Answer the following questions as you proceed.
4. Why are restriction enzymes compared to "scissors"?
5. Why will the DNA fragments be different lengths in different people?
6. What is the purpose of the agarose gel that's poured into the electrolysis tray?
7. Describe how the electrophoresis process separates the DNA fragments.
8. Why are radioactive probes added to the separated DNA fragments?
9. Which of Jimmy's sisters committed the crime?