Student Exploration: Genetic Engineering
Vocabulary: callus, exon, genetic engineering, genetically modified organism, genome, green
fluorescent protein (GFP), herbicide, insecticide, intron, promoter, transcription, transformation
Prior Knowledge Questions (Do these BEFORE using the Gizmo.)
1. What are some things that can damage a farmer’s crops?
Various types of weeds and pests, insects, severe weather conditions (droughts, tornadoes, etc
air and water pollution.
2. What can farmers do to protect their crops?
Many farmers use chemicals like pesticides, herbicides, and fungicides. Farmers
can also use fertilizers to help increase the amount of nutrients in the soil.
Gizmo Warm-up
Many farmers use chemical herbicides to kill weeds and
insecticides to kill insects. Using genetic engineering,
scientists have developed ways to resist harmful crop pests.
In the Genetic Engineering Gizmo, you will use genetic
engineering techniques to create genetically modified corn.
Check that Task 1 is selected. The Gizmo shows petri dishes that contain different strains of
bacteria (white dots) and caterpillars (Lepidoptera sp. larvae). In the first challenge, your goal is
to find bacteria that produce toxins that kill the caterpillars. Click Play ( ).
1. What do you observe? 11 caterpillars died while 37 caterpillars lived.
2. Which strains of bacteria were able to kill Lepidoptera sp. larvae? 4,5,8,10
Were some more effective than others? Explain.
Some were: 4 and 8 killed all four; 5 killed two; 10 killed one
Some bacteria are able to produce a toxin that kills Lepidoptera sp. larvae. Find out which
gene is responsible for this toxin in the next step.
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, Activity A: Get the Gizmo ready:
Caterpillar- Click Reset ( ) and check that Task 1 is selected
resistant corn in the dropdown menu.
Introduction: Lepidoptera sp. larvae (caterpillars) eat corn kernels, leaves, and stalks. In this
activity, use genetic engineering techniques to create a corn plant that is resistant to caterpillars.
Question: How can we produce corn that is resistant to Lepidoptera sp. larvae?
1. Observe: Click Play. Select one of the strains of bacteria harmful to larvae (by clicking on
the plate).
Which strain did you select? 8
2. Investigate: Click Continue. The screen now shows the genome, or set of genes, of the
selected bacteria. One of these genes produces the protein that kills the caterpillars. You
will test each gene by adding it to the genome of a bacteria that does not kill caterpillars.
This process is called transformation.
Drag three genes into the Petri dishes at lower right. These genes are now inserted into the
genomes of the sensitive bacteria in the plates. Press Play. If none of those genes help to
kill the caterpillars, click Reset and try three other genes. When you find a gene that kills the
caterpillars, click on the Petri dish to select the gene that confers resistance.
Which gene did you select? Gene F
In reality, finding a gene with a desired trait is much less common. Scientists search through
many more bacterial strains and potential genes to find the traits they are looking for.
3. Observe: Click Continue. Promoters are regions of DNA that initiate the transcription of a
gene. Some promoters only work in specific types of cells, such as leaf cells or root cells.
To determine which cells of a corn plant a promoter works in, four promoters have been
attached to the Green Fluorescent Protein (GFP) gene. Each promoter-GFP gene has
been inserted into a corn plant. Select Lights off to see the parts of each plant glow green
and fill in the table below.
Promoter Glowing plant part(s) Gene Glowing plant part(s)
1 Roots and leaves 3 Roots
2 Leaves 4 Leaves
Which promoter is active in only the leaves? 4 In the whole plant? 1
Select the promoter you would like to use by clicking on a plant, and then click Continue.
(Activity A continued on next page)
2019