A worm pest eating corn

Genetically Modified Organisms (GMOs) - Corn

Grade 3

Pests can be a major problem for farmers seeking to grow crops. Pests are small insects that eat and feed on crops, thereby killing them. However, farmers and scientists have worked together to come up with solutions to help prevent these pests from eating corn and other crops. Corn bred with a certain genetic trait are less attractive to pests. We will explore how this is possible in this lesson.


Teacher's Guide and Related Standards


I can explain how variation in a certain trait for corn allows some of the species to survive while others have a greater chance at dying off.

Essential Questions

  • How does variation in traits make some organisms of the same species more likely to survive than others?

  • What is a GMO and what advantages do GMOs have over non-GMOs?

Maryland Farm & Harvest Clip

Thinking questions:

  • What are earworms and how do they harm corn?
  • What is Bt corn and how is Bt corn different from other corn?
  • What trait does Bt corn have that makes it able to survive better than other corn?
  • What are the benefits of using Bt over pesticides on crops like corn?


Supplemental Enrichment Activities

Constructing Explanations and
Designing Solutions

Adoption of Genetically Engineered Crops Graph

Analyze the graph. Inform students that HT is similar to Bt in that it allows crops to build resistance against pests.

Upon interpreting the graph, have a discussion about how crop practices have changed over time and why this is the case.

» Go to Graph

Natural Selection

Variation in Corn Color

Explore another trait among corn, which is the kernel color. Ask students what they observe from the image and why some corn appears different from others.

» Go to Image

Cause and Effect


The Maryland Farm and Harvest video described pesticides as being harmful.

Review the information and video from this resource and pose the question: What are the effects of the overuse of pesticides in crop fields and gardens?

» Go to Website

Career Connections


This learning resource is a production of Maryland Public Television/Thinkport, in partnership with the Maryland Agricultural Education Foundation.

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