Genetic Engineering

Author(s)
Bethany Vice and Nick Harth
Subject(s)
Biology - Genetics

Grade Level
th

Duration
60-70 minutes

Rationale (How this relates to engineering)

Allow the students to participate in the first step of genetic engineering. Display the connections
between understanding basic genetics to the application of genetic engineering and its impact on
society.

Activity Summary
Students are introduced to genetic engineering and its impact on society. A review of basic genetics
concepts and discussion of the more advanced concepts of genetic engineering allow students to
understand biotechnology. Then students then participate in the first step of genetic engineering, DNA
extraction, by extracting DNA from their own cheek cells.

Objectives
1. 1. Students will be able to explain the relationship between DNA and genes.
2. 2. Students will be able to discuss how genetic engineering affects their lives.
3. 3. Students will be able to give examples of genetically modified foods.
4. 4. Students will be able to describe why genetic engineering is possible.
5. 5. Students will be able to describe the basic process of genetic engineering.
6. 6. Students will be able to identify the different components of a scientific activity and lab
report.

Standards
Science – Life Science Heredity
% • Illustrate the relationship of the structure and function of DNA to protein
synthesis and the characteristics of an organism.
% • Explain that a unit of hereditary information is called a gene, and genes may
occur in different forms called alleles (e.g., gene for pea plant height has two alleles, tall and
short).

Diversity and Independence of Life

• Describe ways that human activities can deliberately or inadvertently alter the
equilibrium in ecosystems. Explain how changes in technology/biotechnology can
cause significant changes, either positive or negative, in environmental quality
and carrying capacity.

Historical Perspectives and Scientific Revolutions

• Analyze and investigate emerging scientific issues (e.g., genetically modified
food, stem cell research, genetic research and cloning).

Understanding Technology
• Describe examples of scientific advances and emerging technologies and how they may impact
society.

Background Knowledge
Students will already have studied basic genetics concepts (Mendelian inheritance, DNA function) and
probabilities with Punnett squares.

Materials Required
One test tube per person Test tube rack Liquid soap (25% soap, 75% distilled water) Bottled water
Sodium chloride (8 grams NaCl per 92 mL distilled water) Rubbing alcohol Parafilm Pipettes Small
graduated beakers

Activities
(10 min) Warm-up – Begin class with two warm-up questions projected onto the board. These
questions are meant to be thought provoking, getting them to start thinking about genetic
engineering. They may not know what genetic engineering is in technical terms, however they
likely have heard the term and they can reflect on what they’ve heard in the news or they may
want to break down the phrase into “genetic” and “engineering”.

WARM-UP QUESTIONS
What does the phrase “genetic engineering” mean to you?
How has your life, or society as a whole, been impacted by genetic engineering?

(10 min) Engagement Activity – Introduce the topic of genetically modified foods. Students are
shown several different food products that may or may not contain genetically modified food and
asked to identify which contain GM ingredients. This could be treated as a mini “Price is Right”
segment – one of the students participates as the contestant, while the other students are the
audience and allowed to help the contestant choose which product. (70-80% of the foods in the
grocery store contain GM ingredients – cereals, corn products, breads. Generally products that
are labeled “organic” do not contain GM ingredients). The students should then begin to see the
impact genetic engineering has on their lives. A loaf of bread, canned corn, corn tortillas, a box
of rice, cereal, and ketchup were used as examples of foods containing genetically modified
ingredients. Silk soy milk and an organically grown green pepper were used for examples of
foods not containing genetically modified ingredients (picture in presentation of examples).

(10 min) Introduction – Begin with a review of what is the genetic material (DNA), reinforce key
terms (DNA, gene, restriction enzymes, plasmid). When describing the term “gene” give
examples of single traits such as tongue rolling, hitchhiker’s thumb, widow’s peak, etc.
Emphasize that most characteristics (hair color, common diseases, etc.) are not coded for by
single genes but multiple genes. The terms restriction enzymes and plasmid may be new to the
students, likely need to expand on these terms to develop a solid understanding. Discuss the
differences between bacteria and virus (probe the students, many may have good understanding
of this), how viruses infect cells (inserting DNA), and how bacteria developed restriction
enzymes as a defense mechanism to cut-up the viral DNA. Next, describe how scientists utilize
restriction enzymes to cut desired genes of the DNA to be used for genetic engineering.
Next, provide a description of genetic engineering, how it is possible and the basics of
how it is accomplished (diagram available in presentation). Give the students a couple different
examples of genetic engineering in the context of the diagram. Insulin production and pesticides
in crops are two possible examples.
Finally, give the students an overview of what their going to be doing with the activity
and how they are going to create a lab report about their activity. Emphasize the different parts
of a lab report and how it is important to title the report appropriately, introduce the activity,
follow the protocol, make accurate observations, and then develop conclusions from the results.

(20-25 min) Activity – DNA Extraction – Students extract DNA from their own cheek cells
using common household materials. Depending on the students’ capabilities, follow the protocol
as a class, or allow them to perform the experiment independently. Have students read over the
Introduction and Materials and Methods portions before they begin. The students should answer
the questions in the Introduction (including the hypothesis). Demonstrate proper lab techniques
to the students, such as how to correctly use a pipette. Have students perform experiment. At
the final step (addition of alcohol) they should begin to note their observations on their
worksheet (although they should be observing all along, noting the observations after the last
step is key). Students should see two layers – bottom layer is spit, soap, and salt water while top
layer is alcohol and DNA. DNA prefers to be in the alcohol layer and students will see it
gradually move to the stop. Tiny bubbles, thin strands of white, little clumps of white are all
indications that DNA is present. Students should note any changes that occur after letting the
mixture sit after adding the alcohol.
Bring the class together to discuss their observations. The students should compile their
observations into one or two sentences of results and begin to complete the conclusion questions.

(10-15 min) Conclusion – Students finish the questions on the worksheet. Students fill-out feedback
forms.

Lab Safety
Disposed of all materials after one use; do not reuse materials. Inform students to be cautious when
working with their bodily fluids and around other’s fluids due to the spread of disease.
Interdisciplinary – English/writing component
In their English class the students were provided with more information on genetically modified (GM)
foods including a basic overview of GM foods and two articles by scientists with two differing views on
GM foods (one positive and one negative). The students were asked to write a letter to the president
asking him to support or not support GM foods. The students completed a pre-writing activity that
helped them organize their thoughts and then wrote the letter in the appropriate format. A holistic
scoring guide for response to informational text (provided in the materials) was used to grade the letters.

Assessment of Student Learning

Students will be assessed by the worksheet which contains questions that they complete while
performing the experiment as well as post-activity discussion questions. There are ten different
questions for them to answer, possible 5 points for each question.

Assessment of the Activity

Students complete a survey of their opinions of the activity.

Activity Reflection

Instructor A
I think the genetic engineering lesson was generally a success. I was able to show the students
that genetic engineering has an impact on their lives and get them interested in genetics in
general by extracting their DNA. The fact that some of the students wanted to take home their
DNA made me think they were excited about the activity.

The “Genetics is Right” warm-up definitely got their attention. The students immediately
perked-up and began to participate. It was recommended that if done again I could include some
of the food the students frequently eat such as different types of chips. The students really
enjoyed the “game” format of the activity, so I might think about incorporating this format into
future lessons.

Doing the DNA extraction experiment as a whole class seemed to work okay. At times it was
difficult to get everyone’s attention, but I did not feel comfortable just letting them do it by
themselves. I think that explaining to them how to use the pipette helped, but perhaps we could
have a cup of water available for them to practice using the pipette. Just about all of the students
performed the experiment successfully and were able to see their DNA. This indicated to me
that the whole class, step-by-step approach was effective. Many of the students did not like the
idea of “spitting” in class, I think because spitting is kind of personal and they didn’t like doing it
in front of their peers.

I think I could have done a better job of wrapping-up the activity. Some of the students finished
the questions faster than others and it’s always difficult to keep those who have finished quiet.
With better discipline by the teacher, it would have been easier to get everyone back together at
the end. Also, I wanted the students to work on the last few questions independently.

As for changes I would make, next time I would make sure to get graduated pipettes so that the
students would be able to measure the solutions appropriately. This would also reinforce their
measurement abilities. It might also be possible to incorporate the making of the solutions (salt
water, soap solution), giving them practice in measuring.

Although I tried to emphasize writing in this activity, the students were frustrated with the
writing and indicated in the feedback that they did not like all the writing this activity required.
Some of the students almost refused to put their thoughts, knowledge, etc. down on paper. Also,
they did not want to think about a question, especially a question about something we hadn’t just
talked about. Some of the questions required them to reflect on content covered earlier in the
class (weeks or months earlier) and many of them had difficulty with these questions. I think the
students just need more integration of the content areas, reinforcing previously learned concepts.
I know these issues are not unique to my lesson, but perhaps in my next lesson I will incorporate
an assessment piece that does not require them to write (although they need the writing practice),
but would allow them to express themselves in some other form (not sure what that might be?).

Another option would be to make this into a two day activity, where during the second day the students
use the computer lab and actually write their own lab report. Using my recommendations, their books,
the internet, or other resources they could produce something using their own words. I’m not sure if this
would result in a better product since the students seem to have a lot of difficulty writing, but allowing
them more time and resources may help.

Instructor B
The opener used for this activity involved a skit based upon “The Price is Right” with Bob
Barker and there is no doubt in my mind that this set up the class for a great lesson. This allowed
the class to be involved all together and to learn about what they thought they believed genetic
engineering meant and what it really meant. Also using items which all the students know and
have most likely used/eaten at some point really gave it a sense of why this would affect them
and their lives as well, so this was also a great addition to the lesson.

The overall flow of the lesson was about as great as you can plan it I thought. Bethany kept the
classes moving through the lesson so that no groups ran out of time at the end. I think that once
again this lesson showed just how much easier classrooms could run on days like this where
there is an activity going on if there would be more then one teacher in the classroom. After the
first bell in Tom Hart’s room we each kind of had a good idea of where to assist in the room so
that if at anytime anyone had a question we could be right there with a quick response. This also
allowed some more time for each of us as teachers to ask some more investigational type
questions to get the students to think more about what they are working on. Sometimes even a
great lesson can be made even better by the right placement of certain questions throughout the
exercise.

The students, overall, had some great feedback for the activity with the largest dislike being
that they had to work with their own spit. I was thinking of ways to get around this and the one
suggestion I could come up with is to have clean wipes or time for the students to wash their
hands after they have gone through this section. In my mind though, I think that this was really
made out to be a larger dislike then it really was because there were some people in every class
expressing this very vocally and when the feedback forms came around this was the one thing
that could stick in people’s minds that were unsure of anything else they disliked. This
element, the spitting, should remain in the lesson though in my mind because it makes it more a
“this is what MY DNA looks like” rather then the more general “this is what DNA looks.”
Proof of this is that about 5-10 of the students actually took their test tubes home with them to
show their parents what their own DNA looked like. As a teacher, I think that impacting a
student enough that they wish to share what they did that day with their family is a huge
remark to the lesson and the work that the teacher prepared.

The handout used for this lesson was very well organized and designed in a manner that we should
actually try and have the students use it again to see if they get more comfortable with it and give a
more complete write-up. Then maybe after enough of these we could see if the students could come up
with a final product on their own just by using these others as examples to work from. The format of this
handout was great in that it simulated an actually laboratory write-up with all the same components
(hypothesis, observations, conclusion, etc.). The earlier the students get used to this, the easier this will
come for them in a college laboratory. I also believe that the students did like the extra credit question
option and it was here that we really did get some incredible responses which showed the potential for
some of these students