National Agricultural Literacy Curriculum Matrix
From Techniques to Traits
9 - 12
Three 50-minute class periods
This lesson explores common biotechnology methods and their applications in agricultural sciences. Students will examine DNA analysis techniques, become familiar with the process of polymerase chain reaction (PCR), and evaluate methods of DNA analysis as they learn how the biological techniques can be used in the process of developing specific traits within a crop.
Interest Approach - Engagement:
- Environmental Scenario Cards (cut and packaged in a plastic bag; 1 per group)
- From Gene to Trait image (projected for whole class)
- DNA Analysis Techniques Graphic Organizer (1 per student, printed single-sided)
- Scissors and staples, glue, or tape
- PCR Sequencing Cards (cut, shuffled and packaged in a plastic bag: 1 per group)
- Environmental Scenario Cards (from Interest Approach)
- Environmental Stressor Case Study (1 copy per group or student; or projected digitally for entire class)
- Poster or chart paper (1 per group)
- Sticky notes
Essential Files (maps, charts, pictures, or documents)
- PCR Sequencing Cards
- Environmental Stressor Case Study
- DNA Analysis Techniques Graphic Organizer
- Environmental Scenario Cards
biotechnology: the use of biology to solve problems and make useful products
gel electrophoresis: a method for separation and analysis of macromolecules (DNA, RNA and proteins) and their fragments, based on their size and charge
gene: a discrete segment of DNA that codes for a product, typically a protein
genetically modified organism: any organism whose genetic material has been altered using genetic engineering techniques
genotype: the genetic makeup of an organism
phenotype: the observable characteristics of an organism
polymerase chain reaction (PCR): a technique to make many copies of a specific DNA region in vitro (in a test tube rather than an organism)
recombinant DNA: DNA molecules formed by laboratory methods to bring together genetic material from multiple sources
restriction enzyme: DNA-cutting enzymes that recognize one or a few target sequences and cuts DNA at or near those sequences
selective breeding: process by which humans control the breeding of plants or animals in order to exhibit or eliminate a particular characteristic
trait: a genetically determined structure, attribute, or function
Did you know? (Ag Facts)
- Selective breeding has been occurring for thousands of years. Modern corn development began almost 10,000 years ago by selectively breeding a grass known as teosinte.1
- Over 80% of soybeans and corn produced in the United States are genetically modified for insect resistance or herbicide tolerance.2
- In 1909, Nils Heribert-Nilsson first demonstrated how crossing plants and creating hybrids results in plants that are better than the parents. This is known as hybrid vigor.3
Background Agricultural Connections
Interest Approach – Engagement
- Divide students into small groups and distribute one set of Environmental Scenarios Cards to each group. Inform students that half of their cards describe a scenario for growing crops and the other half list a trait that could be found in a crop. Instruct students to read the scenarios and match them with a desired trait for each situation. Encourage students to justify their reasoning for each match.
- Draw on students' prior knowledge by asking them to explain the relationship between a gene and a trait. Have students explain why a certain trait may be more beneficial in a particular environment than another.
- Next, ask students to brainstorm additional environmental stressors that plants may need to overcome. Examples include humidity, pollution, elevation, salinity, pH, and predators.
- Summarize by displaying the From Gene to Trait image. Confirm that students understand that a gene is a segment of DNA that codes for a protein or some functional product (i.e. tRNA, rRNA, etc.). They should also understand there are other regions of DNA that do not code directly for proteins, but may play a regulatory role in gene expression. For example, a farmer can look at a plant that is expressing a desirable trait and breed that plant to further amplify the expression of beneficial genes without necessarily knowing the exact DNA sequence of those genes. Additionally, biotechnology can aid scientists in the identification of gene sequences that lead to beneficial traits, which can help them develop improved crop varieties. This can speed the process of developing better adapted crops, thus increasing yield and reducing food shortage. Image Source: http://ib.bioninja.com.au/standard-level/topic-3-genetics/31-genes/genes-and-loci.html
Activity 1: DNA Analysis Techniques
- Ask students, "Where is DNA found within a cell?" Students should recall from prior knowledge that DNA is found in the nucleus of eukaryotic cells. Remind them that DNA contains genes that code for proteins, which lead to traits.
- Next ask, "If DNA is found within the cell, how can it be viewed or analyzed?" Explain that there are several methods used by scientists to extract, view, and analyze DNA. Today we will be learning four of them.
- Give each student group one copy of the DNA Analysis Techniques Graphic Organizer. Instruct students to set aside page one and cut out the cards on page two.
- Next, have students match the DNA analysis technique to its description and illustration. The three cards can be connected with a staple, glue, or tape.
- Note: Students are not necessarily expected to know these scientific processes yet. The activity is designed to be an assessment of prior knowledge.
- Come back together as a class and share out examples until all of the DNA analysis techniques have been correctly matched and described.
- Have students read the scenario and follow the instructions on page one of their DNA Analysis Graphic Organizer. Students will complete the graphic organizer by placing the DNA analysis technique in the correct portion of the graphic organizer. The goal of this activity is to correctly assess if students understand which DNA analysis technique is appropriate for a given task.
Alternative Approach: This activity can also be adapted to be completed in groups. Print one copy of the graphic organizer per group and challenge students to research each analysis method to complete the activity together.
Activity 2: PCR
- Explain to students that they will be learning more about PCR (polymerase chain reaction), one of the four techniques they were introduced to in Activity 1. Ensure that they understand that the overall purpose of PCR is to amplify (make more copies of) DNA. PCR is a commonly used tool in forensic science, medical and biological research, and agriscience. Being able to have a large amount of DNA to work with is crucial, as opposed to a tiny sample that may be prone to contamination or human error.
- Direct students to read a basic introduction to PCR.
- When students are done reading, place students into groups of 2-3. Give each group a set of PCR Sequencing Cards. Instruct students to organize the cards to illustrate the correct order of the three main steps of PCR. Each step should include a name, description, and a picture as illustrated below.
- Project the cycling image from the Khan Academy site that students saw in step 2. Explain that PCR allows exponential amplification of DNA, and can produce millions of copies of a target sequence in a matter of hours.
- Complete this activity with a reminder of the necessity of doing PCR before most testing and experiments using DNA.
- As an additional extension, students can demonstrate this process on the tabletop using materials such as flash cards, play dough, or markers, and/or create a short video of this process using apps such as Stop Motion Studio (claymation).
Activity 3: Case Study Application and Evaluation
- Return a set of Environmental Scenario Cards to each student group (previously used in the Interest Approach). Also give each group a copy of the Environmental Stressor Case Study, a piece of chart paper, and a marker.
- Note: Rather than distributing hard copies of the case study, you may also choose to project the case study to the whole class.
- Instruct students to consult their DNA Analysis Techniques graphic organizer from Activity 1 and recall previous activities to place the DNA analysis techniques in the appropriate order that they should use to solve the problem in the case study.
- In their groups, students should create a Plan of Action poster to share with the class. Their poster should include three headings:
- DNA Techniques: List the DNA analysis techniques that should be used as well as the order they believe the technologies should be used (and if they should all be used).
- Steps the Researcher Should Take: Include information directly from the student flowchart describing what steps should be taken.
- Anticipated Outcome: Explain the outcome the researcher would hope for.
- After student groups complete their posters, provide sticky notes to students and instruct them to walk around the room and evaluate each other's posters and leave feedback on the posters (i.e. Do you agree with their process? If so, why? Alternatively, if you disagree, why?) They may also leave behind questions and any additional comments they may have. It is important to remind students that they are evaluating someone else's work, so they should be mindful of their feedback and respectful.
- Allow students time to view the feedback left on their poster, and make corrections if necessary.
Concept Elaboration and Evaluation
After conducting these activities, review and summarize the following key concepts:
- Science and biology are used to improve the production of our food and overcome specific challenges in agriculture.
- PCR (Polymerase Chain Reaction) is used to make many copies of specific DNA regions.
- DNA analysis techniques are tools scientists can use in the process of gene identification and manipulation.
We welcome your feedback! Please take a minute to tell us how to make this lesson better or to give us a few gold stars!
Suggested Companion Resources
- Bringing Biotechnology to Life (Activity)
- Animal Biotechnology video (Multimedia)
- Learn GMO (Multimedia)
- Study: People Opposed to GMOs Don't Know As Much About Science As They Think (Multimedia)
- Biotech in Focus (Booklets & Readers)
- Biotechnology Ag Mag (Booklets & Readers)
- Agricultural Biotechnology Questions and Answers (Website)
Agricultural Literacy Outcomes
Science, Technology, Engineering & Math
- Identify current and emerging scientific discoveries and technologies and their possible use in agriculture (e.g., biotechnology, bio-chemical, mechanical, etc.) (T4.9-12.e)
Education Content Standards
Biotechnology Systems Career Pathway
BS.03.04Apply biotechnology principles, techniques and processes to enhance plant and animal care and production (e.g., selective breeding, pharmaceuticals, biodiversity, etc.).
9-12 Geography Standard 14: How human actions modify the physical environment.
Objective 3People can either mitigate and/or adapt to the consequences of human modifications of the physical environment.
HS-LS3 Heredity: Inheritance and Variation of Traits
HS-LS3-1Ask questions to clarify relationships about the role of DNA and chromosomes in coding the instructions for characteristic traits passed from parents to offspring.
HS-LS4: Biological Evolution: Unity and Diversity
HS-LS4-5Evaluate the evidence supporting claims that changes in environmental conditions may result in: (1) increases in the number of individuals of some species, (2) the emergence of new species over time, and (3) the extinction of other species.
Common Core Connections
Reading: Anchor Standards
CCSS.ELA-LITERACY.CCRA.R.7Integrate and evaluate content presented in diverse media and formats, including visually and quantitatively, as well as in words.
Writing: Anchor Standards
CCSS.ELA-LITERACY.CCRA.W.1Write arguments to support claims in an analysis of substantive topics or texts using valid reasoning and relevant and sufficient evidence.
CCSS.ELA-LITERACY.CCRA.W.9Draw evidence from literary or informational texts to support analysis, reflection, and research.