Primary Type: Lesson Plan
Status: Published
This is a resource from CPALMS (www.cpalms.org) where all educators go for bright ideas!
Resource ID#: 75955
A Taste of DNA
"A Taste of DNA" is an activity-based lesson intended to be used as a reinforcement of the concepts associated with the structure of DNA and
building DNA. It covers information pertaining to base pairing, DNA shape and structure, cellular organelles, and the function of DNA. In this lesson
students will have the opportunity to move around the classroom, build a long strand across the science floor, and create their own strand with the
knowledge they've gained.
Subject(s): Science
Grade Level(s): 7
Intended Audience: Educators
Suggested Technology: Computer for Presenter,
Computers for Students, Internet Connection, LCD
Projector, Speakers/Headphones, Adobe Flash Player,
Microsoft Office
Instructional Time: 55 Minute(s)
Resource supports reading in content area: Yes
Freely Available: Yes
Keywords: DNA, Edible DNA, Genetics, Base Pairing,
Resource Collection: FCR-STEMLearn Diversity and Ecology
ATTACHMENTS
Wrap Up Exit Slip.docx
DNA pwrpt.pptx
Base Pair Puzzle.docx
Checklist for DNA Model.docx
LESSON CONTENT
Lesson Plan Template: General Lesson Plan
Learning Objectives: What should students know and be able to do as a result of this lesson?
1. Students will be able to describe the structure and function of DNA.
2. Students will be able to identify the base pairs that form the a double-helix structure of DNA.
3. Students will be able to differentiate between a correct strand of DNA and an incorrect strand of DNA using the rules of base pairing.
4. Students will be able to explain where DNA is located.
5. Students will be able to create a model of DNA.
Prior Knowledge: What prior knowledge should students have for this lesson?
1. This is a reinforcement lesson so students should already have a good foundation of knowledge pertaining to DNA.
2. Prior to the lesson students should understand inheritance as well as cell structure and function.
3. Students should have an understanding of DNA and its role in heredity.
page 1 of 4 4. Students must know that DNA has a spiral double-helix shape and is genetic material.
5. Vocabulary terms include but aren't limited to cell, nucleus, heredity, inheritance, DNA, chromosomes, gene, allele, and double-helix.
Guiding Questions: What are the guiding questions for this lesson?
1. Do we all have the same DNA?
2. Why is DNA so important?
3. How does your DNA look?
4. What is the structure and function of DNA?
5. What makes up a strand of DNA?
Teaching Phase: How will the teacher present the concept or skill to students?
1. To begin the lesson teachers should display different examples for instructions. This could be a recipe, blueprints, or instructions for building a device. Then conduct
a brief discussion on how these items relate to DNA.
2. The teacher will present a BrainPop video on DNA (www.brainpop.com). A great alternative to this video is a YouTube video title "What is DNA?"
http://youtu.be/zwibgNGe4aY . Both videos provide the necessary information to introduce the lesson and prepare students for the activities. Both videos should be
discussed with respect to the guiding questions after viewing.
3. Next, present PowerPoint on DNA (see Attachment) as a refresher of content. The presentation acts more like a class discussion for students to think about terms
and concepts previously covered.
Slide 1: Guide students to state that DNA is an abbreviation for deoxyribonucleic acid.
Slide 2: Defines DNA. This reflects back to the introductory discussion. Students are reminded that DNA is a set of instructions (function).
Slide 3: Photo of a single animal cell. This slide is a "Stop and Jot." Have students answer the following questions in a science journal or on a sheet of paper
and discuss their answers with their table partner.
In which organelle is DNA located?
What is the function of DNA within a cell?
Slide 4: Defines organelle and nucleus. Explains that the nucleus is a cellular organelle where DNA is located.
Slide 5: Shows an example of DNA's shape. Focus on structure and function.
Slide 6: Shows an actual strand of DNA. Pinpoint the base pairs and explain the rules of base pairing in both DNA and RNA. Also consider explaining why this
pairing is important (function).
Slide 7-9: Focuses on vocabulary necessary to achieve the lesson's objectives.
Guided Practice: What activities or exercises will the students complete with teacher guidance?
1. Prior to the lesson there should be base pair cards (see Attachment and Special Materials) printed, laminated, and cut-out.
2. Hand out base pair puzzle cards.
3. Directions:
Each student is handed a stack of 10 cards
Instruct students that they will build a very large strand of DNA using the cards provided.
There cannot be any separate strands being created
The strand can curve around the classroom in any direction they decide (remember the strand may need to snake under desks and around tables to fit into the
classroom).
As one student places a base down the next student may place its appropriate base pair next to it until every student has used all their cards.
Start the strand with one single base and let the students build!
Give the students a 10 minute time limit if necessary.
4. Whole-class activity. In this activity the entire class will work together to build a long strand of DNA around the classroom. This part of the lesson requires
movement and participation of all students. Each student is provided with 10 base pair puzzle pieces. The teacher starts the strand of with any single base. The entire
class stands up and begins to build a strand on the classroom floor. Students will place their puzzle pieces down according to the base pairing rules. Once all students
have placed their pieces down, the classroom floor should be covered with a single strand of DNA. Have students take their seats and as a class identify any mistakes.
The students should recognize any incorrectly paired bases and explain how it can fixed. If no mistakes are present use this time to review the base pairing rules.
5. The last part of this activity is explaining that a DNA strand has a sugar-phosphate backbone. Use some string to represent the backbone. Follow the strand of DNA
to illustrate where the backbone is located.
6. The teacher will ask the class to discuss what a strand the DNA represents (code for traits). Ask the class to discuss what would happen if the teacher had given a
different base as a starting piece. What would this mean in an organism? (different genotype/phenotype).
7. The teacher should also discuss how DNA functions as an agent of heredity. ( DNA carries genetic information that is coded by the patterns of the proteinsrepresented here by ATGCC. Those codes are passed from parent to offspring through genes(specific sequence of DNA).
Independent Practice: What activities or exercises will students complete to reinforce the concepts and skills developed in the
lesson?
Edible DNA Model: This activity is independent practice. Students will create an edible model of DNA. This includes the sugar-phosphate backbone and all bases.
Teacher will instruct class to build a model of a DNA strand using licorice as their base (nucleotide) and gummy bears as their proteins. Students will assemble their
models based on pairing principles.
Supplies: Licorice, toothpicks, gummy bears, masking tape, and gloves.
page 2 of 4 2 pieces of licorice
12 toothpicks
9 green gummy bears
9 red gummy bears
9 yellow gummy bears
9 orange gummy bears
Masking tape
Gloves
While students are working use this time to walk around and ask probing questions. Provide useful feedback based on their responses. Ask questions such as "Which
bases are you currently pairing?" "What does each letter represent?" "What function/purpose do you think the sugar-phosphate backbone serve?" "Will your strand of
DNA be exactly the same as your classmate's strand? Why or Why not?"
Closure: How will the teacher assist students in organizing the knowledge gained in the lesson?
Bring closure to the lesson by returning to the Guiding Questions. This could be done in a whole-group discussion or by having groups discuss questions.
Ask students to complete 3-2-1 Exit Slip (see Attachment). Students will answer the set of three questions in their science journal.
3 Things that make up a strand of DNA
2 Functions of DNA
1 Example of the shape/structure of DNA
Summative Assessment
The teacher will determine if the student has reached the learning goal target using the closure activity. The closure activity resembles a 3-2-1 Exit Slip (See
Attachment). The attachment contains the questions the students will answer as well as the response the teacher should look for.
Formative Assessment
During the Independent Practice Activity, "Edible DNA", this is a great opportunity for teachers to gather information using a Formative Assessment. While students are
working use this time to walk around and ask probing questions. Provide useful feedback based on their responses. Ask questions such as:
Which bases are you currently pairing?
What does each letter represent?
What function/purpose do you think the sugar-phosphate backbone serve?
Will your strand of DNA be exactly the same as your classmate's strand? Why or Why not?
Sticky notes are useful for providing personal feedback to specific student(s).
Feedback to Students
Students should receive feedback throughout the entire lesson. Most feedback can be given during the class discussion and the guided practice activity. More specific
feedback is given in the "Teacher Comments" section of the Edible DNA checklist later in the lesson (See attachment).
ACCOMMODATIONS & RECOMMENDATIONS
Accommodations:
1. To differentiate instruction there should be intentional pairing of students who seem to have a good grasp on the subject with students who do not. Students who
have a language barrier should be paired with students who speak their same language.
2. For students who are gifted or who have mastered the concept, there is a resource on www.explorelearning.com that challenges the students to complete specific
tasks associated with building DNA.
Extensions:
1. Adding a DNA replication component. One side of the DNA strands can be removed and this used as the starting strand to be transcribed to RNA. Here is where
Uracil, Amino Acids, and Codons are introduced.
2. Conducting a DNA Gizmo on www.explorelearning.com. This gizmo allows students to independently build a strand of DNA on their own computer. It shows the
sugar, phosphate, base, and each of their shapes. Once one side is build and arranged however the student chooses, they are then required to build the
complimentary strand. There are explanations of the role of each component of DNA and a quiz that follows the exercise to check for understanding. This tool also has
a "Student Exploration" worksheet that guides the through the activity with tasks and questions to answer.
Note: Gizmo requires a subscription, but has free trial options.
Suggested Technology: Computer for Presenter, Computers for Students, Internet Connection, LCD Projector, Speakers/Headphones, Adobe Flash Player, Microsoft
Office
Special Materials Needed:
1. Guided Activity Material:
Print, Laminate and Cut-out base pair puzzle pieces (See Base Pair Attachment). There should be enough for each student to receive 10 puzzle pieces.
Long String
2. Independent Activity Material:
Print Activity Checklist (See Checklist Attachment)
Gather Supplies: Licorice, toothpicks, gummy bears, masking tape, and gloves.
page 3 of 4 2 pieces of licorice
12 toothpicks
9 green gummy bears
9 red gummy bears
9 yellow gummy bears
9 orange gummy bears
Masking tape
Gloves.
Further Recommendations:
This lesson can be adapted to accommodate lower level students. The activities can be done in pairs or small groups.
SOURCE AND ACCESS INFORMATION
Contributed by: Tomika Knowles
Name of Author/Source: Tomika Knowles
District/Organization of Contributor(s): Broward
Is this Resource freely Available? Yes
Access Privileges: Public
License: CPALMS License - no distribution - non commercial
Related Standards
Name
SC.7.L.16.1:
Description
Understand and explain that every organism requires a set of instructions that specifies its traits, that this hereditary
information (DNA) contains genes located in the chromosomes of each cell, and that heredity is the passage of these
instructions from one generation to another.
Remarks/Examples:
Integrate HE.7.C.1.4. Describe how heredity can affect personal health.
page 4 of 4