Animal Mouth Structures

PBS LearningMedia
Type Category
Instructional Materials
Lesson/Lesson Plan , Instructor Guide/Manual , Informative Text , Image/Image Set
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.



In this activity students examine how the structure of various animal mouthparts affects their function. They will have an opportunity to predict what foods are likely to be eaten by birds with different beak types, watch a video comparing and analyzing snake and human mouth structures, and construct explanations about how other animals' mouths are relatied to their feeding strategies.

NOTE: web page linked has the heading "Part 1" prior to the four steps referenced in this evaluation. There are no further Parts apparent, so the four steps listed under Part 1 appear to be the complete lesson sequence.

Intended Audience

Educational Level
  • Grade 5
  • Grade 4
  • Grade 4
  • Upper Elementary
Access Restrictions

Free access with user action - The right to view and/or download material without financial barriers but users are required to register or experience some other low-barrier to use.

Performance Expectations

4-LS1-1 Construct an argument that plants and animals have internal and external structures that function to support survival, growth, behavior, and reproduction.

Clarification Statement: Examples of structures could include thorns, stems, roots, colored petals, heart, stomach, lung, brain, and skin.

Assessment Boundary: Assessment is limited to macroscopic structures within plant and animal systems.

This resource is explicitly designed to build towards this performance expectation.

Comments about Including the Performance Expectation
This series of activities builds towards achievement of the Performance Expectation, but teachers are encouraged to add elements to the lesson that focus on constructing an argument. Students asked to think about and make predictions regarding the relationship between mouth structure and the type of food best suited to them. To better address this practice, the teacher could ask students to construct an argument citing evidence which may come from the resources provided or from additional sources. The teacher might provide or create with the students a chart identifying key characteristics of mouth structure types and the function/food type suggested by them. Examples and in-depth discussion can be found in the Background Essays under the Support Materials tab in each lesson element.

Science and Engineering Practices

This resource is explicitly designed to build towards this science and engineering practice.

Comments about Including the Science and Engineering Practice
While the practice of constructing an argument about how animal mouth structures are related to the foods that are eaten is explicit, opportunities should be incorporated into the lessons for students to critique the arguments of others. Students could refine arguments and argue from evidence, as well as providing and receiving critiques from peers about proposed explanations. To strengthen understanding of the relationship between the mouth types the available food types, students might discuss or illustrate problems that could occur if animals had different mouth structures that were not effective given the food resources available.

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
The focus of these lessons is animal mouthparts as they relate to obtaining food, so the teacher might encourage students to also consider how an animal's mouth contributes to its survival in other ways, such as defense or mating. The video "Unhinged" discusses the ability of a snake to regurgitate its food to escape a predator if needed. It also discusses the internal structures involved in digestion.

Crosscutting Concepts

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

Comments about Including the Crosscutting Concept
This concept is not fully addressed in this resource. Teachers could emphasize how an animal mouth is made up of discrete structures that carry out the function of obtaining food or other functions. The video of the Unhinged! lesson component refers to specific snake mouthparts that can be used to make this point. Students might also compare their own mouth structures with those of the animals they observe. Teachers could elicit student background knowledge or provide other resources to provide experience with thinking about specialized animal teeth, tongues, jaws, etc. as related parts of a system.

Resource Quality

  • Alignment to the Dimensions of the NGSS: This resource builds toward this performance expectation by providing students with an opportunity to view mouthparts of various animals and construct explanations about their different functions. Two segments concentrate on bird beaks, and a third uses a video for a detailed analysis and comparison of snake and human digestive systems, concentrating on mouthparts. To further address this Performance Expectation, the teacher should relate the various structures considered as subsystems and to consider their interactions within the larger body system of an animal. Teachers might also focus on encouraging students to provide evidence for their predictions about foods they claim are likely to be eaten based on the mouths of animal photos they observe.

  • Instructional Supports: Support materials for the teacher in each phase of the lesson include background information and discussion questions, but little support is provided for differentiation of instruction. An enrichment activity for advanced learners could be having students compare simple tools to bird beak types as a way of furthering their understanding of the relationship between structure and function. The video that goes along with Part 3 of the lesson includes a Descriptive Video option for the vision impaired. An additional resource that would support instruction is the Skulls 3D Viewer Gallery at the website of the California Academy of Sciences ( ).

  • Monitoring Student Progress: While many discussion questions are provided, the resource lacks answers, sample student responses, or rubrics to aid in using them for assessment. Anecdotal evidence of student understanding can be gained from observation of their drawings, as well as their verbal responses.

  • Quality of Technological Interactivity: Students view animal photos and a video to provide information on which to base their explanations and predictions, but the technology is not highly interactive.