Primary Type: Lesson Plan
Status: Published
This is a resource from CPALMS (www.cpalms.org) where all educators go for bright ideas!
Resource ID#: 75790
Suspect Strawberry, DNA testing?
This lesson uses the scientific method to extract DNA from food sources, other than strawberries, to support that DNA is common to almost all
organisms.
Subject(s): Science
Grade Level(s): 7
Intended Audience: Educators
Suggested Technology: Computer for Presenter,
Internet Connection, LCD Projector, Overhead
Projector
Instructional Time: 2 Hour(s)
Resource supports reading in content area: Yes
Freely Available: Yes
Keywords: DNA,
Resource Collection: FCR-STEMLearn Cell Biology
LESSON CONTENT
Lesson Plan Template: Learning Cycle (5E Model)
Learning Objectives: What will students know and be able to do as a result of this lesson?
Students will be able to determine if all living organisms have DNA.
Prior Knowledge: What prior knowledge should students have for this lesson?
Recognize that DNA is a molecule located in the cell's nucleus, and holds genetic information that makes each of us unique and special.
Chromosomes contain genetic material needed for life.
Guiding Questions: What are the guiding questions for this lesson?
Does every life form have DNA? Justify your answer?
Is DNA universal for all organisms?
Engage: What object, event, or questions will the teacher use to trigger the students' curiosity and engage them in the concepts?
Strawberry DNA Virtual Lab:Students will do the following.
Write, in your science notebook, the scientific method requirements a great lab must have in order to be deemed credible.
Discuss and clarify the requirements as a class. They should include testable question, hypothesis, materials, procedure, variables, control, observations, data
analysis and conclusion.
Watch the Strawberry DNA Lab (9:45) using this link: https://www.youtube.com/watch?v=hOpu4iN5Bh4 While viewing the lab, students should fill in each of the
step of the scientific method (see numbers 1 and 2) Pause the video after segments where criteria for filling out each step of the scientific method are addressed.
Post- Strawberry DNA Virtual Lab questions:
Is there DNA in your food? How do you know?(Lab)
What did the DNA look like? Relate your predictions to what you observed. Draw a picture to illustrate your answer. (snotty, clear fibrous..)
A person cannot see a single cotton thread 100 feet away. Is this statement analogous to our DNA extraction? Explain. (Too small)
Why is it important for scientists to be able to remove DNA from an organism? List two reasons. (Genome sequencing, medical reasons, crime scene investigation
type situation)
Explore: What will the students do to explore the concepts and skills being developed through the lesson?
page 1 of 3 Divide the class into groups of 3-4 students.
Tell students," Yesterday, you watched a video of a Strawberry DNA Extraction lab and used the information given to fill in the requirements needed for the scientific
method.
Ask students
Why are strawberries used for this lab? What else could you use?
Explain how you can see the DNA, if it is usually so minute that it fits in the nucleus of each cell of an organism.
Today you and your group are going to complete the statement..."What would happen if the DNA extraction method was performed on ________________" (food
item) and write the statement in your science notebook.
The group is responsible for bringing in the food item that they chose to fill in the blanks.
Students will write the steps for the "new" lab using the Strawberry DNA virtual lab as a guide.
Students will then try and extract DNA from their item.
Note: You may use the following link to print out a PDF of the procedure if needed. http://www.imb.uq.edu.au/download/large/strawberryDNAextraction.pdf
Explain: What will the students and teacher do so students have opportunities to clarify their ideas, reach a conclusion or
generalization, and communicate what they know to others?
The students will watch an animated version of the DNA lesson using the link: https://www.youtube.com/watch?v=4NegABEGTv4
They will read the article "DNA structure" from How stuff works, using link : http://science.howstuffworks.com/life/cellular-microscopic/dna1.htm and answer the
questions at the end of it, to learn more about DNA.
Students will write a conclusion for their DNA extraction lab. The conclusion mus include:
Whether the hypothesis was supported or not supported.
Data/observations which justify the whether the hypothesis was supported or not.
Explain how your experiment answers the question: "Do all living organisms have DNA?
Elaborate: What will the students do to apply their conceptual understanding and skills to solve a problem, make a decision,
perform a task, or make sense of new knowledge?
Students can also elaborate on their knowledge by explaining why bacteria can be used to make insulin.
Summative Assessment
Students will write a conclusion for their DNA extraction lab. The conclusion mus include:
Whether the hypothesis was supported or not supported.
Data/observations which justify the whether the hypothesis was supported or not.
Explain how your experiment answers the question: "Do all living organisms have DNA?
Formative Assessment
The teacher can project the following questions on the screen one at a time. Formative questions: Answer the following questions, and justify your answer.
Today we are going to work with strawberries, do they have DNA? If so, what does it look like?
Why do strawberries need DNA? Do all the plants have DNA?
Does every living thing have DNA? If a person is dead, does the body still have DNA?
Feedback to Students
As students are working on their formative assessment, teacher is walking around the teams, and monitoring them. Teacher is also listening for appropriate answers
to the discussion questions.You can take a count the answers verbally, or written down on a chart. Tell them the correct answer if 70-80% of the students get it, move
to the next question. If their answers are dispersed, then ask probing questions to nudge them to face their misconceptions and to correct them.
Examples of these probing questions are as follows.
Is your genetic material found in your thumbs, brain, muscles, liver? (you want to hear "everywhere")
Is it found inside of your body or outside?(inside)
ACCOMMODATIONS & RECOMMENDATIONS
Accommodations:
ESE students: Use buddy system where students are paired up according to their FCAT reading scores, 2-4, 1-3, 3-5. Have cooperative or group learning
opportunity for students when ESE students can learn from their peers, and every one sharpens their skills in the process.
ELL students: Have bilingual dictionaries or Google translate help the ELL students, along with placing them in a group of bilingual students if available.
Students are working in groups for the lab. Arrange the students in using any of the following criteria for cooperative learning. The criterion can be FCAT score,
learning modalities, ESE and ELL needs. Place, on each student's desk, a label with letters identify teams.
Suggested Technology: Computer for Presenter, Internet Connection, LCD Projector, Overhead Projector
Special Materials Needed:
Cell lysing solution
91% alcohol
Filter and ice bath for DNA extraction lab.
Further Recommendations:
Have the desks arranged in the configuration of the desired group size, with labels and/or name tents made of index cards.
SOURCE AND ACCESS INFORMATION
Contributed by: Surbhi Jinandra
page 2 of 3 Name of Author/Source: Surbhi Jinandra
District/Organization of Contributor(s): Seminole
Is this Resource freely Available? Yes
Access Privileges: Public
License: CPALMS License - no distribution - non commercial
Related Standards
Name
SC.912.L.16.9:
Description
Explain how and why the genetic code is universal and is common to almost all organisms.
page 3 of 3