Plants and People: Nutrition and Technology
Grade level: 7-9
State Standards
 Concepts and processes: Life systems
-Levels of organization in living systems
-Diversity of organisms
 History and nature of science in personal and social decisions
Student background knowledge
-flower parts and reproduction
-monocots and dicots,
-hydroponics
- plant nutrition.
Day 1
“You are What you Eat”: Human Nutrition and the World of Plants
Time: 60 minutes
Goals

Students will understand that there is an abundance of plant diversity with
agriculture representing a few important families

Students will understand that the functions of various plant parts/organs tie closely
to human nutrition

Students will understand that the commonalities and differences of plants are both
determined by genetics that have changed over millions of years.
Objectives

Students will be able to describe examples of plant organs and the common
characteristics of these anatomical parts

Students will determine how characteristics of each of these parts fit into human
nutrition.

Students will be able to analyze scientific materials to gain knowledge and
understanding of a topic
Guiding Questions

What parts of a plant do we rely on for food and energy?

If these plant parts are useful to us, how are they also useful to the plant?

Is plant diversity natural or man-made?
Engage
Choose a plant family with particular relevance to the region where the school is
located. For example, Lovell, Wyoming is also known as “Rose City” because this shrub
grows well in the climate. Roses are in the family Rosaceae.
Does Rosaceae just refer to the flowers we call roses? How many types of rose ARE
there? Draw classification scheme on the board:
Kingdom Plantae -- Plants
Subkingdom Tracheobionta -- Vascular plants
Superdivision Spermatophyta -- Seed plants
Division Magnoliophyta -- Flowering plants
Class Magnoliopsida -- Dicotyledons
Subclass Rosidae
Order Rosales
Family Rosaceae -- Rose family
Genus Rosa=garden roses
What are some other plants in the Rosaceae family? Show some examples of
variations within this family. Members of the rose family: rose, serviceberry, strawberries,
raspberries, cinquefoil, mallow ninebark, cherries, plums, thimbleberry, spiraea (avens),
almonds, california holly (“Hollywood”), pears, apricots, peaches....
Pass around a few examples/snacks of plants within the plant family chosen.
Examples of Rosaceae plants: almonds, strawberries, apple slices, rose and rose hips. What
plant parts do we humans use from members of the rose family besides just the pretty
flowers of Rosa….? Make a big list on the board (should include fruit, seeds/nuts, leaves,
etc. as well as flowers).
Explore
Students should brainstorm and write down the similarities and differences between
these important plant parts: what are the necessary features of each of these plant parts and
why?
Explain
To review a little bit, have students work with the person next to them to draw out
the major steps of a life cycle of a plant, making sure that all of the plant parts listed on the
board are incorporated somehow. Students should feel free to use their textbooks or notes
from previous classes.
Humans use plants in different ways based on what part of the plant we want and
how we can use it. Different plant parts have different nutritional values…but WHY?
Revisit functional parts of a plant, or organs (humans aren’t the only one’s with an
anatomy and specific organs!)
Elaborate
Students will take on the role of plant biologists working to communicate their
understanding to the public. Students will work in groups of 3-4 to develop an
advertisement for one of the major organs or functional parts of a plant. The goal is to
market the particular plant part as an important addition or contribution to our daily diet.
Students should think about what their plant part can contribute that is essential to human
nutrition and health. Students will be assigned to one of the following:
-Roots and tubers
-Shoots and leaves
-Flowers
-Fleshy fruits
-Seeds and hardened seed coverings
Teacher will hand out specific student resources to each group, including a rubric for
the short project. Groups will have 20-25 minutes to work through materials and design
advertisements. Advertisement should contain: a diagram of where and how this particular
organ fits into the biology or life cycle of an angiosperm plant. The finished product should
be interesting and convince people that they should include it in their diet or that this plant
part makes important contributions to human health and nutrition.
Evaluate
Students will present their advertisements to the class. Teacher will assess work
using the attached rubric. Time for question-and-answer between student groups.
Wrap-up
Revisit guiding questions. Both man-made and natural plant diversity influence how
we use plants. We rely on some plants more than others. What plant part have humans
come to rely on most? Is diversity within our diet still important? Some other plant families
are important to human civilization. Fit Brassicaceae (cabbage, mustard, turnips), Poaceae,
and Fabaceae (peas, beans), etc. into the classification scheme on the board.
Materials: various examples (edible or non-edible) of a particular plant family, background
info/diagrams to hand out to students, project rubric, poster board, markers/colored
pencils, colored and white paper.
Day 2
Frankenfoods or Miracle Crops?
Goals

Students will understand the basic principles that enable scientists to create
genetically modified foods

Students will understand the various perspectives surrounding the production and
use of genetically modified plants
Objectives

Students will describe the important steps in creating a transgenic plant

Students will create research questions based on background knowledge of
biotechnology

Students will be able to critically read scientific material, analyzing for bias and
perspective in scientists’ conclusions
Guiding Questions

What are genetically modified plants and how are they different from other plants?

Why are scientists creating transgenic plants?

Are genetically modified foods bad for you?
Background:
Biotechnology does not equal genetically modified foods. Biotechnology applies to
the crop breeding that has been going on for 8 thousand years as well as grafting, tissue
culture and other manipulations of plants and animals.
One of the main purposes of genetic modification is to improve crops in a more
financially or time efficient manner. More specifically, purposes of creating GM plants
include disease resistance, drought or cold tolerance, salinity tolerance, and increased ability
to take up nutrients. Another main purpose is to create useful pharmecuticals or by-products
from plants (more basic biotechnology). Some GM plants produce plastics (Michigan
scientists developed plant that produces polyhydroxybutyrate). Also we commonly see
biopesticides developed in transgenic plants. For example, Bacillus thuringiencis compounds
are expressed in corn and potato. New horizons in the field of transgenic plants include
nematode-bacteria complexes that kill insects via infection.
Many transgenic plants are produced via culture tissue with bacteria Agrobacetrium
tumefaciens (the bacteria that normally causes crown gall disease in plants). A. tumefaciens
carries the gene of choice and inserts it into the plant cells nucleus, where it is taken up by
the plant DNA. This bacteria is naturally “promiscuous” and inserts its DNA into the plant
and the plant begins to express it. Other transgenic plants, particularly the monocots are
transformed with a gene gun. This alternative, while not as effective, is necessary for grain
crops because A. tumefaciens does not infect it.
It is important to keep in mind that expression of genes is something regulated at
many levels- it is influenced by hormones, enzymes, chemicals, etc.. In a strand of DNA,
genes are preceded by a promotor and operator. The promotor signals transcription of
RNA and the operator regulates genes.
Process of creating genetically modified plants:
-isolate the gene you want (mapping)
-make lots of copies of it (to be on the safe side, and so you have a lot to work with) (PCR)
-add a promotor to make sure it is expressed (usually this is an altered form of cauliflower
mosaic virus, found naturally in Brassicas…one risk is that this promotor leads to
recombination, a possible risk.
-transfer DNA to totipotent plant cells using a “gene gun” or soil bacteria
-check to make sure gene made its way into DNA of plant and is being expressed (via
marker gene that causes chemical signal, fluorescence, or antibiotic resistance)
Engage
Tie today’s lesson to yesterday’s lesson with story about one example of a genetically
modified plant that has received a lot of attention: transgenic fruit with a fish gene. Why
did scientists develop this plant? Is it part fish? How is this process similar and different to
crop breeding that produced commercial strawberries from small tart wild strawberries? In
general, there are a lot of myths out there, as well as a lot of unanswered questions. We will
investigate some of these issues for the rest of the period.
Explore
In groups, students will rotate throughout the room, visiting exploration stations.
Students will spend 5-10 minutes at each station, taking notes along the way. Station topics
include:
1. purpose(s) of creating genetically modified plants
Teacher will provide real world examples of various genetically modified plants with
a short explanation. Ask students: Why would scientists develop genetically modified
plants? Can you think of 3 roles these plants play based on the examples provided here? (for
resources see references below)
2. Are genetically modified foods bad for you?
3. Steps in the process
Teacher will provide computer with internet access. Students will complete the
simulation of creating a transgenic plant from the “Harvest of Fear” website created by
Frontline and NOVA (http://www.pbs.org/wgbh/harvest/engineer/).
4. DNA and a plant cell under the microscope
Students will try to organize various pictures from largest to smallest in scale to help
them understand how genetic expression fits into a cell
-plant leaf
-plant cell
-cell nucleus
-chromosomes
-DNA double helix
Explain
Students will regroup and debrief the exploration stations as a class.
Elaborate
Students will receive one of two short articles about genetically modified foods.
Students will read the materials carefully and then discuss the pros and cons of genetically
modified foods with each other.
Evaluate
Based on the exploration stations and two articles, students will describe the various
perspectives or biases expressed in the articles and brainstorm 3 questions they believe still
need to be addressed concerning genetic modification of plants. What science do these
authors rely on? What plant science is missing?
Wrap-up
Genetic modification of plants is a very exciting field of science and requires the
participation and knowledge of the public and responsible action on the part of the
scientists.
If time, teacher will show students a quick video of plants with firefly fluorescing
gene linked to expression of circadian rhythm genes. For final assessment, have students
take turns explaining the steps in the process that led to this amazing event!
References
Armstrong, W.P. 2007. Wayne’s Word: 15 July 2007.
http://waynesword.palomar.edu/ecoph17.htm (8 October 2007)
Chrispeels, M.J., and Sadava, D.E. 1994. Plants, Genes, and Agriculture. (available
online). Jones and Bartlett Publishers: Boston.
Chrispeels, M.J., and Sadava, D.E. 2003. Plants, Genes, and Crop Biotechnology. Jones
and Bartlett Publishers.
Colorado State University. “Transgenic Crops: An Introduction and Resource Guide”.
(http://cls.casa.colostate.edu/TransgenicCrops/history.html)
PBS. 2001. “Harvest of Fear”. (http://www.pbs.org/wgbh/harvest)
Taiz and Zeiger (2002). Plant Physiology (3rd ed.)
USDA, Natural Resources Conservation Service: Plants Database
(http://plants.usda.gov/java/ClassificationServlet?source=display&classid=Rosacea
e)
Young, P. 1982. The Botany Coloring Book. Coloring Concepts, Inc. Oakville, CA.