Pre-Lab: Extracting DNA
Problem What properties of DNA can you observe when you extract DNA from cells?
Materials self-sealing plastic freezer bag, ripe strawberry, detergent solution, 25-mL graduated cylinder, cheesecloth, funnel, test tube, test tube rack, chilled ethanol, stirring rod
Lab Manual Chapter 12 Lab
Skills Focus Predict, Observe, Draw Conclusions
Connect to the Not surprisingly, the molecules that store genetic information are long molecules. If the DNA from a human cell were unfolded, the double helix structure would be about one meter long. Yet, most of a cell's DNA can be folded and tightly packed inside the cell's tiny nucleus. How can scientists remove DNA from the nucleus so that it can be studied and analyzed? In this lab, you will learn that extracting DNA from living tissue is not as difficult as you might think.
Review Describe the structure of a DNA molecule.
Review What type of bond holds the strands of DNA together?
Apply Concepts How does the strength of those bonds affect how DNA functions?
Preview the procedure in the lab manual.
Apply Concepts Why do strawberry cells need DNA?
Form a Hypothesis If you observe a cell nucleus under a compound microscope, you will not see a molecule of DNA. Why will you be able to see the DNA you extract?
Predict Use what you know about DNA to predict some of the physical properties of DNA.
Design an Experiment How could you determine what percentage of a strawberry's mass is DNA?
Visit Chapter 12 online to test yourself on chapter content and to find activities to help you learn.
Untamed Science Video The Untamed Science CSI crew unravels the secrets of DNA left at the scene of a crime.
Art in Motion View an animation that re-creates the Hershey-Chase experiments.
Art Review Review your understanding of both prokaryotic and eukaryotic DNA replication.
InterActive Art Drag-and-drop base pairs to build your own strand of DNA while you practice the process of DNA replication.
Data Analysis Learn how analysis of DNA base sequences can be used to track animal poaching.
Tutor Tube Tune into the tutor to find out hints for remembering which bases pair together.
Visual Analogy Compare transcription and translation with the process of publishing a book.