Title: Strawberries and their DNA
Audience: 7-8th graders
Duration: 50-60 minutes
Objectives: Students will extract DNA from a strawberry.
Students will observe DNA.
Students will understand that DNA in plants can be manipulated to get
desirable traits.
Process Skills: Observing, Communicating, Inferring
Standards:
Environment and Ecology
4.4.7B Explain how species of living organisms adapt to the environment.
4.4.7C Define issues associated with food and fiber production.
Science and Technology
3.3.7B Describe the cell as the basic structural and functional unit of living things.
3.3.7C Know that every organism has a set of genetic instructions that
determine its inherited traits.
Reading, Writing, Speaking, Listening
1.6.8A Listen to others (ask probing questions and analyze information).
1.6.8D Contribute to discussions.
Materials: (per pair of students)
Quart Ziplock freezer bag15 mLs of cold ethanol in test tube
#2 Coffee filter10 mLs of DNA extractor buffer
5 oz. plastic cup(see Lab instructions)
Plastic pipetteStrawberry
Lab worksheet
Anticipatory Set:
1. Start with this simple scenario: Pretend you are a farmer who is trying to create the perfect strawberry for consumers to buy. You want a strawberry that is easy to grow, easy to harvest, but also sweet to taste and healthy-looking. Upon trying several types of seeds and different types of growing methods, you still aren’t satisfied with your strawberries. Is it possible to create a perfect strawberry?
2. Questioning: How does a plant get its traits? How do you? (genes, DNA) Can traits be changed? (For humans, we can change how we appear, ie. hair color, eye color, but our genes don’t change.) Can DNA be changed on humans? Plants? (discuss) Why would we want to change our DNA make-up? (discuss) Why would farmers want to change it? (discuss)
Procedures:
1. Review the plant cell and its parts using previous lesson material.
2. Read through the Lab procedures as a class first (see below), and be sure all pairs understand the procedures.
3. Each pair works together to complete the Lab DNA extraction.
4. Pairs record their observations during the experiment.
5. Pairs record answers to the questions at the end of the extraction.
6. When completed, discuss the findings as a whole group.
Closure/Evaluation: Teacher observes pairs while Lab extractions are taking place. Students record observations. Then, return to the scenario at the beginning of the lesson and review and discuss.
Lab Procedures for DNA Extraction from a Strawberry
Materials are listed above. Work with a partner.
1. Remove the stem and leaves of the strawberry.
2. Place the strawberry in the ziplock bag.
3. Mash up the strawberry for 2 minutes while it is in the bag.
4. Add the 10 mLs of the extraction buffer (soapy, salty water) to the bag and mix together.
5. Place the coffee filter over the plastic cup. Fit the filter over the rim of the cup, and do not let the filter touch the bottom of the cup.
6. Empty the mashed strawberry and buffer into the filter and let it drip into the cup.
** This will take some time. Be patient as the mixture filters through.
7. When the strawberry and extraction buffer have finished filtering, get a test tube with the cold ethanol in it.
8. Using the pipette, put some of the mixture into the test tube and observe what happens.
9. Record your observations of the alcohol and mixture interacting. Draw what you see.
10. You are looking at strawberry DNA as it separates from the rest of the material.
11. Answer the questions below:
What does the DNA look like?
If you can extract (or pull apart) this DNA, what else could be done with it?
How does this experiment show you what could be possible with plant DNA?
Source: Pioneer Hi-Bred International, Inc., 2003 Educational Services Program
Title: What’s SO Great About Soybeans?
Audience: 3-4th graders
Duration: 30-40 minutes
Objectives: Students will identify household products that contain soybeans in them.
Students will explain the importance of agricultural products in their daily
lives.
Students will define renewable and nonrenewable products.
Process Skills: classifying, comparing, communicating
Standards:
Environment and Ecology
4.4.4B Identify products derived from natural resources.
4.4.4A Know importance of agriculture.
4.4.4B Identify the role of sciences in PA agriculture.
4.4.4C Know that food and fiber originate from plants and animals.
(Describe the journey of local agricultural products from product
to consumer.)
Reading, Writing, Speaking, Listening
1.6.3D Contribute to discussions.
1.6.3E Participate in small and large group discussions and presentations.
Materials: Soybeans in the Story of Agriculture by Susan Anderson and JoAnne Buggey
Chart paper
Markers
5 Small Tupperware containers with soybeans inside
Anticipatory Set:
Mystery Seeds/Beans: Put students into cooperative groups of 4-5 students. Give each group a container of the soybeans. Have each group respond to the following:
What are they? How do you know? Describe what’s inside the container.
Have each group record answers on chart paper with markers.
Procedures:
1. Have a spokesperson from each group share the responses from the above activity.
2. Discuss and question after the correct identification has been made. How many of you have eaten soybeans? Seen them? Know what they are used for?
3. Introduce the book Soybeans in the Story of Agriculture. Read pages 1-18 and 27-33. Use some general discussion as you read. (How are soybeans grown? Renewable vs. non-renewable, Where are they grown? Why are they an important crop in our country?)
4. In same groups, make a list on the back of the chart paper of some products that come from soybeans.
5. For homework: Assign students to go through their food pantries, cupboards, cabinets, etc. and look for items that are made from soybeans or have soybeans in them. Each student is to list the items he/she finds to share with the class the following day.
(Items can include-but aren’t limited to-bread, muffins, pasta, flour, cereal, edamame, vegetable /soybean oil, soy milk, tofu, soynuts, Prang crayons, soy candles, soy ink)
Closure/Evaluation:
Questioning and discussion during the first part of this lesson can be used to be sure that students understand the importance of agricultural products in their daily lives. When the homework assignment is completed, students can as groups compile lists with drawings of the items they found in their own homes that have soybeans in them.