The Arizona Hedgehog Cactus: Endangered Species or Not?
Polymerase Chain Reaction Amplification of DNA

Assignment: After listening to the in-class explanation of PCR, reading your background information and studying the diagrams provided, answer the following questions.

1. Briefly explain the steps involved in normal DNA replication within a cell before mitosis.






2. What is the function of each of the following in a PCR reaction?

3. Briefly describe what the thermocycler (PCR machine) does and what happens in each of the following three steps of Polymerase Chain Reaction:

4. Suppose you start with one double-stranded molecule of DNA and you want to amplify this one DNA molecule by PCR. You add an excess of a two single-stranded primers, each of which will anneal to the DNA molecule in only one place, copying the segment of DNA between them. Draw representations of the DNA and primers in each of 3 cycles. Label the template DNA, the primers, and the newly synthesized DNA strands. Show the direction of DNA synthesis on each strand.











How many molecules of double-stranded DNA will you have after three cycles? After six cycles? After 100 cycles?



5. Compare the normal process of DNA replication within a cell to the artificial replication of DNA molecules in a PCR machine. Describe what is different between these two processes.








6. What kinds of changes to chromosomes would cause a "polymorphism" to appear in the DNA profiles of different individuals from a population?






How would a deletion in the chromosome of one individual cause a band to run closer to the wells in a gel?







[CONTINUE || TABLE OF CONTENTS || GENERAL BIOLOGY PROGRAM]


Science Education Connection
Department of Biochemistry
The University of Arizona
May 1, 1997
warder@u.arizona.edu

http://biology.arizona.edu/sciconn/lessons/alongi/
All contents copyright ©1997. All rights reserved.