Unit 3 — Structures and Functions
Description
Students develop an understanding that plants and animals have internal and external structures that function to support survival, growth, behavior, and reproduction. The crosscutting concepts of systems and system models are called out as organizing concepts for this disciplinary core idea. Students are expected to demonstrate grade-appropriate proficiency in engaging in argument from evidence.
Essential Questions
- How do the internal and external parts of plants and animals support their survival, growth, behavior, and reproduction?
Learning Objectives
- Construct an argument that plants and animals have internal and external structures that function to support survival, growth, behavior, and reproduction
- Describe a system in terms of its components and their interactions
- Construct an argument with evidence, data, and/or a model
Supplemental Resources
- Printed images of various organisms and their structures
- Graphic organizers for comparing internal and external structures
- Index cards for categorizing organism structures
- Chart paper for recording evidence of structure and function
- Markers for creating diagrams and visual displays
Life Sciences
Students read informational texts and conduct short research projects to gather evidence supporting science explanations across all units. They write informative and opinion pieces, take notes from print and digital sources, draw evidence from texts, and use audio recordings and visual displays in presentations to communicate understanding of science concepts including weathering, erosion, earth processes, structures and functions, energy transfer, force and motion, and waves.
Students apply mathematical reasoning and measurement skills across science units. They use measurement units to collect and analyze quantitative data, model with mathematics when drawing diagrams of light and waves, solve multistep word problems involving distances and quantities related to energy and earth processes, interpret multiplication equations as comparisons when analyzing environmental data, and apply geometric concepts such as points, lines, angles, and lines of symmetry when studying wave properties and organism structures.
Formative Assessments
- Students describe a system in terms of its components and their interactions
- Students construct an argument with evidence, data, and/or a model
- Students construct an argument to support the claim that plants and animals have internal and external structures that function to support survival, growth, behavior, and reproduction
Summative Assessment
Design a zoo that is organized by animals with the best sense receptors and describe how having those sense receptors helps animals survive
Benchmark Assessment
— not configured —
Alternative Assessment
Students may demonstrate understanding through a labeled diagram or model of a plant or animal structure with oral explanation of how each part functions for survival, rather than a written argument. Visual supports such as sentence frames, word banks, or graphic organizers showing structure-function relationships may be provided as needed.
IEP (Individualized Education Program)
When constructing arguments about plant and animal structures, provide graphic organizers that separate the claim, evidence, and reasoning sections so students can organize their thinking before writing or speaking. Allow students to demonstrate understanding of internal and external structures through labeled diagrams, oral explanation, or a model rather than written argument alone. Offer sentence frames to scaffold the language of scientific argumentation (e.g., 'My claim is… The evidence shows… This supports my claim because…'), and pre-teach key structural vocabulary using picture-supported reference cards students can use throughout the unit.
Section 504
Provide extended time for tasks that require students to construct written arguments about plant and animal structures, and allow access to a quiet or low-distraction setting during formative tasks. Preferential seating near instructional visuals—such as diagrams of internal and external structures—supports sustained focus during discussions and direct instruction. Ensure printed copies of any content displayed digitally or on the board are available so students can reference material at their own pace.
ELL / MLL
Build vocabulary for structural and functional terms (e.g., internal, external, survive, reproduce, sense receptor) using labeled visuals, bilingual glossaries, or picture dictionaries before and throughout the unit. Provide simplified directions for argument-construction tasks and encourage students to sketch or diagram their understanding of plant and animal structures as an entry point before transitioning to verbal or written explanation. Where possible, connect the concept of animal survival structures to examples familiar across different cultural environments to make the content more accessible and meaningful.
At Risk (RTI)
Activate prior knowledge by connecting the concept of body structures to students' everyday experiences with plants and animals before introducing formal scientific vocabulary. Reduce the complexity of argument-construction tasks by beginning with a single structure and a clear, guided example of how that structure supports survival before students apply the framework independently. Use visual models and hands-on exploration of structural features to build confidence and comprehension, allowing students to demonstrate understanding through discussion or annotated drawings when extended writing presents a barrier.
Gifted & Talented
Challenge students to move beyond identifying individual structures by analyzing how multiple internal and external systems interact to support an organism's overall survival strategy, drawing comparisons across plant and animal kingdoms. For the summative zoo design task, encourage students to incorporate original research into lesser-known species with specialized sensory structures, evaluating trade-offs between different sense receptor adaptations in varying environments. Students may also explore the engineering design connection—how understanding biological structures has inspired human-designed technologies—to extend their thinking into cross-disciplinary depth.