Seed StartersResource ID#: 47116 

This MEA presents a non-profit group that helps start schools gardens. This client is looking to switch to a tomato seed that is adapted to increased moisture in the soil due to precipitation and is versatile and great tasting. The engineering team will examine the seeds presented and develop a procedural method to rank the seeds based on the client's needs. The engineering team will reach a decision as to the best choice of seed for the client.

Subject(s): English Language Arts, ScienceGrade Level(s): 5Intended Audience: EducatorsSuggested Technology: Computers for Students, Internet Connection, Basic Calculators, Microsoft OfficeInstructional Time: 5 Hour(s)Keywords: Science, Plants, MEAInstructional Component Type(s): Lesson Plan,  Model Eliciting Activity (MEA) STEM LessonInstructional Design Framework(s): Cooperative LearningResource Collection: STEM Lessons - Model Eliciting Activity

Lesson Plan Template:  Model Eliciting Activity (MEA) Formative Assessment

The comprehension questions/readiness questions and reflection questions can be used as formative assessment (for questions, see the Readiness questions section). Comprehension and readiness questions will indicate whether the students understand the problem and the problem context, and reflection questions are meant to elicit students’ thinking as they are working through the problem. The comprehension/readiness questions are asked of students after they read the first client letter (see Reading Passage 1). The teacher can ask the class to respond to these questions and ensure understanding before students begin working with the data.

Students’ responses to the reflective questions can also indicate whether scaffolding is needed. The reflection questions are asked by the teacher as students are working in their groups on parts 1 and 2 of the MEA. These questions can reveal any misunderstanding or issues that students have as well as guide them to think about what they are doing.

Summative AssessmentTo assess MEA solutions: Quality Assurance Rubric, developed by Purdue University's Case Studies for Kids Project. Accessible at the following link: Case Studies for Kids Assessment 

Writing Rubric: Text-Based Writing Rubrics. Learning Objectives

Students will be able to categorize, analyze and make recommendations of the different seed types based on their particular adaptations to different environments to satisfy the client's needs.

Prior KnowledgeStudents must have an understanding of the plant life stages and items necessary for plants growth.

Instructional SuggestionsDiscussion what plants need prior to activity. Read Client Letter #1 and assign student teams. Ask students to create a ranking procedure to solve the client's problem. Then read the second client letter. Have students team revise their ranking procedures to find the best

solution to their client's problem. Ask students to write back a letter to the client explaining their procedure and provide their decision.

Suggested Technology: Computers for Students, Internet Connection, Basic Calculators, Microsoft Office

Links

Lima bean adaptation article and video http://aplus.com/a/atlas-obscura-lima-beans (This link may contain language that is inappropriate for children. Copy parts from it that you want to use.

http://www.spcpweb.org/factsheets/KidsGuidetoPesticidesBW.pdf Kid’s Guide to Pesticides

http://discovermagazine.com/2002/apr/featplants Background knowledge for teachers – plant adaptation.

Guiding/reflective Questions

1. Given current changes in the weather patterns, how will you choose the best seed type based on hardiness and water needs for the school gardens?

2. How will you ensure that versatility for the different regions in the school district will be included in the seed selection?

3. Can you give school garden coordinators an ideal of number of plants they can grow per square foot in the gardens and potential yield?

4. How much does planting time affect seed selection?

Readiness Questions (For reading passage/letter 1)Do students understand the needs of a plant in order to solve the problem?

Can students explain the purpose of adaptations for plants and animals to survive in different environments?

Comprehension/readiness questions

1. Do students understand who the client is and what their needs are?2. Are students able to demonstrate an understanding of adaptations among different

plant species?3. Students should be able to explain that differences in soils and precipitation can occur

in the same region and that adaptations are related to these differences.

Reading Passage 1

Sally Seed Starters 1234 Main Street Miami, FL

Dear Engineering Team,We are a non-profit organization that helps start school gardens for students all across Florida. We are looking for a new tomato seed to use in garden projects. We are specifically looking for organic heirloom tomato seeds and we have narrowed down our choices to 4 different seed selections. Since we are a non-profit we need to have a good cost of seeds ratio, hardiness, watering requirements and how high the tolerance to insects is. The last but very important factors are taste and versatility. We want our students to love to eat what they grow and allow each school to use the tomatoes is salads, pasta sauces, etc. I will give you the information on the next page. Can your team please rank the best seeds for our organization and provide us with an explanation as

to how you arrived at your decisions?

Sincerely, Sally

Data Set 1

Name Price per Ounce

# of seeds/oz. Hardiness Watering Resistance to Insects

Harry’s Heirloom $3.25 20/oz. Moist soil-every day

Average

Coastal Heirlooms $3.50 25/oz. Moist-dry soil twice per week

High

Florida’s Finest

Heirlooms

$2.75 35/oz. Moist-dry soil twice per week

Average

Heirloom Sweet Heirloom $3.50 25/oz. Moist soil – every other day

High

Name Reviewer #1 Reviewer #2 Reviewer #3 Reviewer #4Harry’s Heirloom Really Yummy and juicy. Beautiful large

tomatoes, very delicious.

I think this tomato is so good it can be eaten right off the vine.

Very tasty tomato.

Coastal Heirlooms

Very watery tomato that tasted a little mushy.

No flavor. Very bland.

We used our tomatoes on a pizza and they tasted good.

This tomato was really watery.

Florida’s Finest

Heirlooms

Great tasting tomato. This tomato tasted really good in our salad.

This was good tasting tomato but not very juicy.

Delicious tomato.

Heirloom Sweet Heirloom

This tomato tastes like a really fresh tomato, you can smell the tomato before you take a bite!

Juicy and delicious.

Very sweet tomato but it seemed too sweet for our pasta sauce.

A mouth-watering delight

Letter Template 1Date:

Dear Sally,

Our Team, _____________________________________, has determined that you should use _______________________as the seed for your school gardens. The ranking of the seeds are as follows:

1.

2.

3.

4.

We made this decision by:

____________________________________________________________________________________________

____________________________________________________________________________________________

____________________________________________________________________________________________

____________________________________________________________________________________________

___________________________________________________________________________________________.

Sincerely,

Reading Passage 2

Sally Seed Starters 1234 Main Street Miami, FL

Dear Engineering Team,Thank you for your hard work. The information you provided was very helpful. However, we have found another possible seed to present to you in your rankings. We have also found that spraying plants with pesticide to keep the insects from eating the tomatoes can be harmful to humans. Some plants have adaptations that protect them from insects, these plants may be healthier because we would not have to spray them with bug spray.

Another concern is that we have a great variety in the types of soil and amount of precipitation across the county and we need a seed that is adapted to these different conditions. It also has to taste good. I would appreciate it if you could rank the seeds with the new information. Please let me know what changes you make, if any, to arrive at your decision.

Sincerely, Sally

Data Set 2

Name Price per Ounce

# of seeds/

oz.

Hardiness Recommended Soil

Watering Resistance to Insects

Recommended Planting

Harry’s Heirloom

$3.25 20/oz. Moist, Organic soil

Moist soil-every day

Average November 1-December 1

Coastal Heirlooms

$3.50 25/oz.

Will grow in mosttypes of soil

Moist-dry soil twice per week

High October 1-December 1

Florida’s Finest

Heirlooms

$2.75 35/oz.

Will grow in most types of soil

Moist-dry soil twice per week

Average October 1-December 1

Heirloom Sweet Heirloom

$3.50 25/oz.

Moist, Organic soil

Moist soil – every other day

High November 1- December 1

Pride of Provence

$4.00 30/oz.

Moist, Organic soil

Water twice a week

Average November 1-December 1

Name Reviewer #1 Reviewer #2 Reviewer #3 Reviewer #4Harry’s Heirloom Really Yummy and

juicy.Beautifullarge tomatoes,very delicious.

I think this tomato is so good it can be eaten right off the vine.

Very tasty tomato.

Coastal Heirlooms Very watery tomato that tasted a little mushy.

No flavor. Very bland. We used our tomatoes on a pizza and they tasted good.

This tomato was really watery.

Florida’s Finest Heirlooms

Great tasting tomato.

This tomato tasted really good in our salad.

This was good tasting tomato but not very juicy.

Delicious tomato.

Heirloom Sweet Heirloom

This tomato tastes like a really fresh tomato, you can smell the tomato before you take a bite!

Juicy and delicious. Very sweet tomatobutit seemed too sweet for our pasta sauce.

A mouth-watering delight

Pride of Provence Delicious, perfect tomato.

Hearty, rich tomato taste.

This was the best tomato I have ever eaten.

We used these tomatoes in our salads and even made a pizza. Yum!

Letter Template 2

Date:

Dear Sally,

Our Team, _____________________________________, has determined that you should use _______________________as the seed for your school gardens. The ranking of the seeds are as follows:

1.

2.

3.

4.

We did/ did not have to change our original procedure. We made our decision using the following procedure:

____________________________________________________________________________________________

____________________________________________________________________________________________

____________________________________________________________________________________________

____________________________________________________________________________________________

___________________________________________________________________________________________.

Sincerely,

Why Lima Beans Are Way More Hardcore Than You Think

By Lisa Winter March 16, 2016"And the lima bean laughs and laughs"

If you've ever said lima beans are boring, get ready to eat your words.

This unassuming plant has evolved one of the most awesome defense

mechanisms in the plant world.

Yeah, you read that right. While humans tend to think of plants just

sitting there unable to fend for themselves, some species are able to able to

fight back against predators in pretty interesting ways.

As far as lima beans go, one of their biggest threats are caterpillars

that eat their leaves. While the plant might not be able to take care of the

intruder directly, it does have the ability to call in reinforcements.

As a recent video from Atlas Obscura explains, when the caterpillar

bites into a lima bean leaf and tears off a piece, the plant emits a chemical

distress signal. This smell attracts wasps, who need caterpillars for a very

important part of their life cycle.

What happens to the caterpillars when the wasps get there? Check out the

video and find out:

Lima beans you scary!

It's actually a pretty smart system. The plant lets the wasp know when there

are available hosts for their young, and in turn, the wasp takes care of the

pest that is eating the plant. It's a win-win. Well, except for the caterpillar.

The caterpillar definitely loses.

This article is included here to provide teacher background knowledge.FROM THE APRIL 2002 ISSUE

Talking PlantsPlants have more than thorns and thistles to protect themselves—they can cry for helpBy Sharman Apt Russell, Max Aguilera-Hellweg|Monday, April 01, 2002

RELATED TAGS: UNUSUAL ORGANISMS, AGRICULTURE

Ian Baldwin works in a lab anyone could love: a large blackened burn area high

on a steep slope in the Great Basin Desert of southwestern Utah. Here a distant mountain range shimmers blue and lavender, the nearer craggy cliffs of Veyo Ridge hover in red, and the curves of the desert hills are dotted green by Joshua trees and scrub. Baldwin, a biologist and the director of the Molecular Ecology Department at the Max Planck Institute for Chemical Ecology in Jena, Germany, has stationed his equipment here to launch a new study of how plants defend themselves—a question he has pursued for 20 years.

He and his colleagues are using chemical sensors to investigate plant communications: cries for help, invitations, even warnings, each in the form of odor molecules that float past human noses unnoticed. The harder biologists look for these signals, the more they find. They have already discovered that plants can send chemical cues to repel insect enemies, as well as signals that attract allies—other insects that are pleased to eat the insects eating the plant. But that is only the start of a more complex scenario, for Baldwin and others have also found that nearby plants can listen in to this conversation and gear up their own defenses.

"Eventually, we will use the information we get here to breed agricultural crops that call out to their insect allies more loudly and more consistently," says Baldwin.

The scorched area they're studying was struck by lightning a year ago, clearing the hillside of juniper and sagebrush. Smoke from the fire triggered the germination of wild tobacco seeds dormant in the soil, yielding a field of Nicotiana attenuata. Baldwin's team has tagged many of them for experiments, using Popsicle sticks and small flags made of red nylon. Chatting in German and English, Baldwin's colleagues look expectantly for golden eagles. The day is hot, the air scented with desert cliff rose.

Tobacco plants are good subjects because they

Above: Ian Baldwin and his team set up equipment in the Utah desert to monitor wild tobacco's chemical defenses against enemies like caterpillars (shown below). Baldwin had not expected to detect any effects. "The fact that it worked was an amazing surprise," he says. "I turned from a skeptic to a believer. The nice thing about research is you can prove yourself wrong."

must be especially agile with their defenses if they are to survive. The seeds can lie dormant for over a century between fires, so the plants may face new enemies once they start growing. Moreover, when the seed germinates, it has only one season to flower and reproduce—and avoid being demolished by insects. "It has to optimize its growth, and it has to strategize against herbivores, always watching the bottom line, which is setting seed," says Baldwin. "These plants have an amazing plasticity. They have to respond to the environment, which is always changing. A number of insect species feed on N. attenuata, and it is a different mix of species every year."

Successful seedlings must fend off the caterpillars of certain hawkmoths, not to mention leaf bugs, flea beetles, and tiny mirids. Baldwin and Andre Kessler, a graduate student, have helped nature along by bringing with them laboratory-raised caterpillars. They place a hungry caterpillar on several of the plants. Over the next few days, they return with a solar-powered gas chromatograph to detect molecules emitted by the damaged leaves. They also check to see what nearby control plants, sans caterpillars, are doing.

Scientists have known for some time that plants can activate powerful defense systems, much as humans churn out antibodies to defend against pathogens. When a caterpillar bites into a leaf, for example, the plant recognizes compounds in the insect's saliva and initiates a chemical defense. Many plants produce toxins (nicotine works well) to kill the insect, as well as compounds that slow down or stop the invader's ability to digest the plant.

Should that fail, there is a second line of defense. A tobacco plant under attack also releases a blend of airborne chemical repellents. In one recent study, Baldwin and Kessler were able to identify, isolate, and test some of these emissions. When they combined the specific chemicals into a paste and smeared it on the stems of plants that had not yet been attacked, hawkmoths avoided laying eggs on them.

Baldwin wanted to find out whether tobacco plants had even more weapons in their arsenal. So he designed an experiment to see if they could summon help. First, he treated the plants with a range of synthetic pastes. Sometimes the paste contained only one of the volatile compounds they had earlier identified, and sometimes it contained a blend of these compounds. Next, they glued the eggs of hawkmoth caterpillars to the underside of the treated plant's leaves. Then they kept an eye out for Geocoris pallens, an insect that likes to eat the eggs. Sure enough, three of the compounds emitted by tobacco plants seemed to attract G. pallens, a small, fast, and rapacious predator.

"By releasing certain volatiles, a plant can reduce the number of herbivores attacking it by as much as 90 percent," Kessler says with admiration. "Chemical signaling is normal. This kind of communication is normal. I think it is probably going on all the time, all around us."

Baldwin explains how he thinks the signals developed. "You're wounded. You emit something. An insect responds. A mutualism evolves."

Baldwin is one of the first in his field to investigate chemical signaling among plants in the wild. Previous experiments had focused on signaling in domesticated crops, and all that work was done in controlled environments, in bell jars and labs and greenhouses with altered atmospheres. Wind tunnels were supposed to mimic one of nature's wilder forces.

Some of the most complex studies came out of these controlled environments. In 1988 Marcel Dicke and his colleagues at Wageningen University in the Netherlands offered evidence that plants under insect attack could enlist help from the enemies of their enemies. Dicke found that when spider mites attack lima bean plants, the plants release a chemical SOS that attracts another mite that preys on the spider mite. Mechanically damaged plants do not produce the cues; most likely, only elicitors in the saliva of the insect can trigger the plant to produce the right molecules. "Today," Dicke says, "the scientific community agrees that plants talking to their bodyguards is likely to be a characteristic of most, if not all, plant species." Even the gingko—a species that has been around for 150 million years—can communicate chemically with insects, he adds.

For example, when caterpillars feed on corn, tobacco, and cotton, the beleaguered plants produce airborne chemicals that attract parasitic wasps. The chemical cries for help are quite specific, attracting only the wasps that lay their eggs in the type of caterpillar infesting the plant. "Plants are not just saying, 'Yes, I am damaged,' they are also saying specifically who is damaging them. It is such an intricate and fabulous system," says Consuelo De Moraes, an assistant professor of entomology at Pennsylvania State University.

Plants can also time the release of different signals to have different effects. Parasitic wasps hunt during the day, for example, so that's when infested plants release their SOS. Plants time the emissions of repellents as well. In studies of commercial tobacco, De Moraes and her colleagues found that caterpillar-infested plants release a chemical blend at night that seems to discourage nocturnal moths from laying eggs that in turn would produce tobacco-devouring caterpillars.

The idea that plants can signal insects has long made sense to scientists. But the concept that plants can communicate with other plants has not, as Baldwin learned back in the early 1980s while still an undergraduate at Dartmouth College. He was studying trees with biologist Jack Schultz, and in 1983 they published a controversial hypothesis: Airborne chemical cues from damaged maple and poplar trees seemed to boost the chemical defenses of undamaged trees nearby. The Secret Life of Plants, a best-seller in the 1970s, had sold the public on the notion of talking to philodendrons, and now it seemed the philodendrons were talking back. Inter-tree communication! Maples whispering to other maples! Reports in the popular press about Baldwin and Schultz's work appeared first in the National Inquirer and later in both People and The New York Times. Scientists were dismissive, and the resulting furor made it difficult for Baldwin and Schultz to get further studies funded.

A series of photographs taken in the lab of entomologist Consuelo De Moraes shows how some plants can summon help when they're attacked. (A) The common crop pest Heliothis virescens feeds on a tobacco plant. Chemicals in the caterpillar's saliva prompt the plant to release airborne chemical cues. (B) Those signals summon Cardiochiles nigriceps, a parasitic wasp that prefers to lay its eggs in H. virescens. (C) The wasp wrestles with the caterpillar, ultimately laying a single egg inside it. When the egg hatches, the larva feeds on the caterpillar, eventually killing it. De Moraes's work has shown that the cues are tailored to attract specific insect allies.Photographs courtesy of A. Sourakov and Consuelo M. De Moraes.

Time, persistence, and good science has changed attitudes. Several months ago Dicke helped produce a special issue of the journal Biochemical Systematics and Ecology filled with papers on plant-to-plant communication. Researchers now find it reasonable that plants can pick up on—and use—each other's signals. "If plants talk to their bodyguards," says Dicke, "then why would their neighbors not take advantage of that and eavesdrop on the message? The topic of plant-to-plant communication is back on the agenda, and the evidence is accumulating."

Dicke and his colleagues have found that mere exposure to airborne emissions from mite-infested cotton and lima beans will prompt undamaged plants to release signals that summon an enemy of the infesting mite. Over the last 19 years, in various experiments, researchers say they've caught willow, poplar, alder, and birch trees listening to their own kind and barley seedlings listening to other barley seedlings. In each case, damaged plants, whether eaten by caterpillars, infected by fungus or powdery mildew, infested by spider mites, or even clipped mechanically, sent out chemicals that seemed to jump-start the defenses of undamaged plants nearby. Researchers are also testing soil to see if plants release chemical warnings from their root systems.

Even unrelated plants can pick up on chemical alarms. Studies by Baldwin's team and others have shown, for example, that sagebrush normally emit an airborne version of a defensive signal; cut or wounded sagebrush release more than six times as much of the signal as unharmed sagebrush. Tobacco plants transplanted downwind of the wounded sage suffer less insect damage than tobacco plants transplanted downwind of unwounded sage. Other studies have found that cucumbers seem to respond to the signals of injured lima beans.

"We have been slow to appreciate," says Jack Schultz, now a professor of entomology at Penn State, "that plants do many similar or even identical things when responding to insects that they do when responding to pathogens. A completely parallel story may emerge here in the way plants detect nearby infection and gear up for it."

Still, biologists who study plant signaling are careful not to overstate their results. Schultz, who continues to collaborate with researchers like Consuelo De Moraes, believes that Baldwin's pioneering research outside the laboratory brings us much closer to understanding how plants communicate chemically in a natural ecosystem. But Schultz cautions that more experiments must be done. Biologists haven't yet documented the signal traveling from plant A to plant B, and many variables can influence a plant's response: wind, drought, light, touch, and disease. "There are a lot of interacting factors to be sorted out," he says.

Dicke adds that individual plants respond differently to insect attack. How they respond may depend on the availability of nutrients and whether the plant would rather invest in growth or defense. Or it may depend on the age of the plant and whether it would rather focus on growth or reproduction. Or it may depend on the previous experience of the plant, which might strengthen its response.

"Showing how things work outdoors is crucial," Schultz says, "but it is not at all easy."

Information from the wild, where few researchers have ventured, could lead to truly revolutionary changes in agriculture. Farmers now rely on heavy pesticide use because domestic plants, which have been bred for high yield, have often lost their native chemical defenses and cannot call out for help. A wild cotton plant, for example, can emit up to 10 times more airborne emissions that summon parasitic wasps to attack infesting caterpillars than a hybrid can.

"Crop plants have been selected for improved yield and high-quality yield and for resistance to pests and disease," explains Dicke, "but never for compatibility with biological control. The latter is essential for the development of durable and environmentally benign pest control. In nature, plants are exposed not only to herbivores but also to a multitude of those herbivores' natural enemies. In agriculture the number of natural enemies is usually reduced because agricultural systems are usually much more simple. Those

A wild tobacco plant grows on a burned site in southwestern Utah. It must deploy an arsenal of chemical weapons to keep voracious insects at bay. "It's remarkable that any part of the world is still green," says Baldwin.

natural enemies that are there—or that we introduce there—should be cherished, and their labor conditions should be optimized so as to take full advantage of their services."

Researchers in developing countries are already using knowledge of plant communications to devise arrangements that push pests away from one crop and pull them toward another target. In East Africa, where stem-borer caterpillars devour fields of maize and sorghum, planting molasses grass in the fields pushes pests away. The molasses grass emits airborne chemicals that repel stem borers and attract the caterpillar's predator, a parasitic wasp. At the same time, plants that stem borers like to eat can be grown around the fields, pulling the pest from the main crop. To some extent this mimics what good gardeners have always known intuitively: Certain plants seem to do well together.

Baldwin and Kessler hope their research indicates nature-based pest control might be easily adapted to many plant varieties. The wild tobacco plant, they've found, emits an array of common compounds that attract an all-purpose insect ally whose tastes range from caterpillar eggs to leaf bugs and mirids.

"The natural system may not be so fine-tuned or so specialized that we can't reproduce it fairly easily," Baldwin says. "We don't have to get it perfectly."

It's nearing dusk, and Baldwin and Kessler are setting up their equipment. Silhouetted against blackened brush, Baldwin pauses to listen to a bird. "Sounds like an oriole," he says.

"No," says Kessler, "a mockingbird imitating an oriole."

The landscape around them is filled with chatter. Some of it can be heard; some of it must be sensed. Signals are being sent. Information is being exchanged. Like gossips tilting their heads in the direction of a juicy conversation, both men lean down, bending closer to a tobacco plant.