Challenge students to design their own experimental protocol to extract DNA from strawberries. By developing their own protocol and presenting their findings in a lab meeting, students learn the importance of making claims with evidence and reasoning and communicating those claims.
Overview
In this lesson, students participate in lab activity designed to help them define qualities that result in reliable and meaningful scientific research. Students are asked to develop an experimental protocol for extracting DNA from whole strawberries. By having students create their own procedures, students learn the importance of making strong arguments in science as they use evidence and reasoning to support their claims. They also communicate, collaborate, and skeptically evaluate each other’s claims. After each group tests their initial protocol, students present their findings in a l class seminar discussion based on a lab meeting in order to collectively “make sense” of their findings. During the lab meeting, students use the class’s “norms of discourse” to skeptically and collaboratively develop a new combined class protocol. Teams then repeat the lab activity using the class-developed protocol
DETAILS:
1 Lesson plan
Step 1: Complete Short Survey
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DNA Extraction: Protocol Design Teacher Guide
Design your own protocol from strawberries and conduct a lab meeting to discuss results. Practice making claims with evidence and reasoning to communicate results and develop a final class protcol.
DNA Extraction: Protocol Design Student Handout
Student document for the design your own protocol from strawberries.
DNA Extraction: Journal Article
National Science Teachers Association (NSTA) The Science Teacher February 2019 issue on the DNA Extraction Protocol Design activity.
DNA Extraction: Protocol Design (Middle School Version)
The DNA Extraction: Protocol Design materials adapted for use in a middle school classroom. These materials were adapted for the middle school level by Justin Priddy, a science teacher at Gateway Middle School (Everett, WA) as a participant in the 2021 Hutch Fellowship for Excellence in STEM Teaching.
DNA Extraction Resource Cards
Resource cards with information about each reagent available for students to develop their protocols.
Online DNA Extraction Resource Cards
Check out SEP teacher Hannah Crowder's website for an online flipcard version of the DNA Extraction Resource Cards.
"Stupidity" in Science
This lesson was created by NWABR for Lesson 2 of The Nature of Scientific Research. In this lesson, students participate in a text-based discussion of the article “The importance of stupidity in scientific research” by Martin Schwartz. Using evidence found in the text, students consider how success is defined in scientific research.
SEP Teachers-Only Quick Links
These links are for SEP teachers who are part of the kit loan program. To become a part of the kit loan program you must complete the 3 week professional development program.
Classic DNA Extraction Resources
Classic Strawberry DNA Extraction Protocol
Extract DNA from cells using steps and reagents similar to those used in research labs and learn the methods involved in DNA isolation.
Graphic Lesson
This protocol uses images to describe the various steps of the extraction, and is useful for younger learners.
Teaching Overheads
A step-by-step explanation of the function of each ingredient in the lysis solution.
Web Resources for Size & Scale, Powers of 10 Concepts
Morphology and Physiology of the Strawberry
Go deep into the strawberry plant with this article by G. M. Darrow.
Plant C-value Database (DNA content per cell)
C-value is the haploid amount of nuclear DNA per cell in a species. This database is hosted by the Royal Botanical Gardens or Kew Gardens. You can use this information to estimate the maximum amount of DNA you might extract from a plant tissue sample.
The Strawberry Plant Defense Mechanism: A Molecular Review
While you are at the Kew Gardens main page, take a look at the videos and the scientific research links. This website is a splendid resource on plants.