Food for Corn

Page Keeley
Type Category
Assessment Materials
Assessment Item
This resource, vetted by NSTA curators, is provided to teachers along with suggested modifications to make it more in line with the vision of the NGSS. While not considered to be “fully aligned,” the resources and expert recommendations provide teachers with concrete examples and expert guidance using the EQuIP rubric to adapted existing resources. Read more here.




This Formative Assessment Probe from The “Uncovering Student Ideas” series is a great way to engage the students to consider how plants get energy and what would be considered “food” for a plant.  Used at the start of a lesson progression, this probe allows the teacher to determine what students think and misconceptions they may have about the processes of photosynthesis and cellular respiration.  The probe is a great segway into a class discussion about the definition of “food” and will allow students to develop early ideas about cellular energy.  The prompt is simple enough for most middle schoolers to relate to yet can drive a more complex discussion if students have background knowledge.  It is advised that the teacher does not disclose the correct response after the initial administration of the probe.  Instead, the teacher can use the probe as the instructional sequence is completed, in order to check for understanding along the way.  In addition, the probe could be used summatively at the end of the lesson progression since the students can demonstrate a conceptual understanding as they justify their response.

Intended Audience

Educational Level
  • Grade 8
  • Grade 7
  • Grade 6
  • Middle School
Access Restrictions

Available for purchase - The right to view, keep, and/or download material upon payment of a one-time fee.

Performance Expectations

MS-LS1-7 Develop a model to describe how food is rearranged through chemical reactions forming new molecules that support growth and/or release energy as this matter moves through an organism.

Clarification Statement: Emphasis is on describing that molecules are broken apart and put back together and that in this process, energy is released.

Assessment Boundary: Assessment does not include details of the chemical reactions for photosynthesis or respiration.

This resource appears to be designed to build towards this performance expectation, though the resource developer has not explicitly stated so.

Comments about Including the Performance Expectation
Due to the nature of a formative assessment probe, it would be best to use this at the start of a lesson progression that will build students’ knowledge of how plants make, store, and use sugar through the processes of photosynthesis and cellular respiration. Use of this probe will give students an opportunity to begin developing a model of how matter and solar energy are needed for plants to make “food” and how the food can be stored until the plant uses it during cellular respiration. After administering the probe, students should be given an opportunity to defend their choice. As the class discusses the various choices from the probe, a model of the processes could be sketched on chart paper and adjusted as students offer ideas. Students should also record their own personal model of the processes within their scientist notebook so they can record new ideas independently of the group. These individual ideas can be presented when revising the chart paper.

Science and Engineering Practices

This resource was not designed to build towards this science and engineering practice, but can be used to build towards it using the suggestions provided below.

Comments about Including the Science and Engineering Practice
Models can be diagrams that show flow of energy and cycling of matter into and out of a system, such as a corn plant. By using one style of arrow to represent matter and a different arrow to represent energy, students can diagram their initial understanding. Labeling each arrow with the type of matter or energy would be another part that could show students’ initial ideas. These models can then be referred back to throughout the lesson progression so students can revise their ideas or add extra labels and/or arrows.

Disciplinary Core Ideas

This resource appears to be designed to build towards this disciplinary core idea, though the resource developer has not explicitly stated so.

Comments about Including the Disciplinary Core Idea
This probe is a formative assessment tool that will allow the teacher to determine the knowledge that students have prior to the lesson progression. As the lesson progression is implemented, students will develop more understanding of the concepts within the core idea and be able to build on the model that they initiate with this probe. The teacher should encourage the use of arrows and labels to show their initial ideas. The details will allow the students to reflect on what they initially thought as their understanding of the concept develops. At the end of the lesson progression, the teacher should revisit the probe with students. Use of the probe in a summative method would be appropriate since the students would have the ability to explain why sugar is the “food” for the corn plants.

Crosscutting Concepts

This resource is explicitly designed to build towards this crosscutting concept.

Comments about Including the Crosscutting Concept
By using a systems approach to the model, students will identify the plant and its surroundings as the natural system. As they develop the model and use arrows to show energy flow, the students will be able to track the energy as it enters the plant from the sun, gets stored in the bonds of the sugar molecules, and eventually used as food during cellular respiration to give provide energy for cellular functions. Teachers should be sure that the final model that students develop explicitly shows the path of the energy in order to meet this crosscutting concept.

Resource Quality

  • Alignment to the Dimensions of the NGSS: This probe is aligned to the NGSS but needs to be part of a lesson progression. The probe is one tool for assessing prior knowledge and engaging students in thoughts/discussion about the source of food for plants.

  • Instructional Supports: The teacher will be able to use the data from the initial use of the probe to determine what ideas the students need to develop in order to reach a conceptual understanding of the chemical processes that plants use to create, store, and use “food.” The initial administration of the probe should be combined with group and/or class discussion but the correct response should not be revealed at that time. By leaving the students wondering which response is correct, the teacher will be able to revisit the probe during the lesson progression to see if students can eliminate responses or narrow the possible correct responses down. Each time it is revisited, the teacher can collect data to see what each student is understanding and what instruction is needed to meet the intent of the performance expectation.

  • Monitoring Student Progress: This probe is an outstanding formative assessment tool since the students have many options that they have to consider and they need to justify their choice. Taking the time to have group and/or class discussions about their choice and their justification is a great way to have students participate in discourse and learn from each other. As they discuss the ideas, mental models will begin to form, which can be transferred to paper for others to see. The probe can also be used as a summative assessment at the end of the lesson progression since students will be able to demonstrate a conceptual understanding as they justify their response.

  • Quality of Technological Interactivity: - none -