Twisting the
DNA Helix
Maria Helen de Hitta-Catalan
What are Genetically
Modified Food (GMF) ?
 Food
that contain an added gene
sequence
 Food that have a deleted gene
sequence
 Animal products from animals fed with
GM feed
 Products produced by GM organisms
Why are food
genetically modified?
 Genetic
modification offers a rapid
and precise method of altering
organisms as compared to
traditional methods that are slow
and inaccurate.
Common GM Food
Vegetables
 Tomatoes
 Potatoes
 Rice
 Cheese
 Meat

How is genetic
modification possible?


The components of DNA are the
same in all organisms.
Sequences that code for proteins
can be moved from one organism
to another.
How can DNA be moved from
one organism to another?
Find an organism with the desired
trait
Isolate the gene sequence that
codes for the desired trait
Insert the gene sequence into the
genome of the plant cell
How can DNA be moved from
one organism to another?
Allow the genetically altered
cell to grow into a plant
Allow the plant to propagate
How can DNA be moved from
one organism to another?

A vector can
carry DNA. The
vector can be a
pellet from a
gene gun.
Viruses and
bacteria can also
be utilized to
transfer genes.
Sources:

Genetics Science Learning Center
http://gslc.genetics.utah.edu/

The Biology Project – Mendelian Genetics
http://www.biology.arizona.edu/mendelian_genetics/mendelian_genetic
s.html

Genetics Education Center
http://www.kumc.edu/gec/

DNA: Heredity and Beyond
http://library.thinkquest.org/20830/

Biotechnology: An Information Resource
http://www.nal.usda.gov/bic/
So, what do you think about
genetically modified food - are
they beneficial or harmful?
To find out more, your
tasks…
Ask good questions, access current
and relevant information, analyze
the validity of resources and the
information, reach consensus with
your peers, take action, and explain
your stand - all in an effort to
answer the question:
Are genetically modified foods
beneficial or harmful?
Specifically, you need to
do the following:
Read articles from Web sites using
Internet search engines to find
information on genetically modified
foods.
 Conduct a survey to find out the
perceptions of a sample population
on GMF.
 Choose a stand. Are GMF beneficial
or harmful?

Specifically, you need to
do the following:
Process the data you gathered
using a spreadsheet application.
 Present survey results to the class
using graphs and tables through a
PowerPoint presentation; and
 Prepare a brochure that informs
the public about GMF and its risks
and benefits, which will in a way
support your stand.

Your performance will be
assessed based on…




how you process information
how you support your point of view
how you effectively communicate
your ideas, and
how you collaborate with your
peers
How your outputs will be
evaluated
You will be working in groups and
outputs will be evaluated using the
following rubrics:
Multimedia Presentation Rubric and
 Brochure Rubric

Remember,
Your individual grade will be
equivalent to the grade your group
will get for this project.
This project will constitute 25% of
your grade for the quarter.
Remember also to…
keep an open mind, and try not to
reach a conclusion before your
investigation is complete.
So,
Investigate!
Collaborate!
Share!