Structure & Function

Life Science
Structure and Function in Living Systems

Living things are diverse with many different characteristics that enable them to grow, reproduce and survive.

Benchmark: Structures & Functions

Compare how the different structures of plants and animals serve various functions of growth, survival and reproduction.

For example: Skeletons in animals and stems in plants provide strength and stability.

Benchmark: Groups of Plants & Animals

Identify common groups of plants and animals using observable physical characteristics, structures and behaviors.

For example: Sort animals into groups such as mammals and amphibians based on physical characteristics.

Another example: Sort and identify common Minnesota trees based on leaf/needle characteristics.


Standard in Lay Terms 
  • Students will be able to identify how different structures of plants and animals help them grow, survive and reproduce.
  • Students will categorize plants and animals based on their physical characteristics, structures and behaviors.
  • Students will use the following vocabulary: physical characteristics, similarities, differences, structures; mammals, birds, reptiles, amphibians, insects.

(from Edina Public Schools, Edina, MN: GRADE 3 Units & Essential Questions)

Big Ideas and Essential Understandings 

Big Idea:

Plants and animals can be classified based on their characteristics and behaviors and these diverse characteristics can be classified as essential for survival, growth, or reproduction.

Benchmark Cluster  Compare how the different structures of plants and animals serve various functions of growth, survival and reproduction.  Identify common groups of plants and animals using observable physical characteristics, structures and behaviors.

This standard is closely linked to Benchmark Give examples of differences among individuals that can sometimes give an individual an advantage in survival and reproduction and Benchmark Students will maintain a record of observations, procedures and explanations, being careful to distinguish between actual observations and ideas about what was observed.  For example: make a chart comparing observations about the structures plants and animals.


NSES Standards

National Science Education Standards: K-4 The Characteristics of Organisms: Each plant or animal has different structures that serve different functions in growth, survival and reproduction.

Life Science: Content Standard C: All students should develop understanding of the characteristics of organisms:

Guide: Each plant or animal has different structures that serve different functions in growth, survival, and reproduction.  For example, humans have distinct body structures for walking, holding, seeing, and talking.

AAAS Atlas

Big Ideas


Similarities and Differences

Diversity and Survival

Student will understand that the individuals of the same kind differ in their characteristics, and sometimes the differences give individuals an advantage in surviving and reproducing. 5F/1

Benchmarks of Science Literacy

By the end of 5th grade, students should know that :

  • A great variety of living things can be sorted into groups in many ways using various features to decide which things belong to which group. 
  • Features used for grouping depend on the purpose of the grouping.

Framework for K-12 Science Education

Plants and animals  have both  internal  and external  structures that  serve various  functions  in growth,  survival, behavior, and reproduction. 5LS1.A

Scientists have identified and classified many plants  and animals.  Populations of organisms  live in a variety of habitats, and change in those habitats affects the organisms  living there. Humans, like all other  organisms, obtain  living and nonliving resources from their environments5LS4.D

Common Core Standards



A. Data and Statistics

Represent and interpret data in real world and mathematical problems.

1. Read and interpret data from circle graphs using halves, thirds and quarters.

2. Collect data using observations or surveys and represent the data with pictographs and line plots with appropriate title and key.


C. Measurement: Measure and calculate length, time, weight, temperature and money using appropriate tools and units to solve real-world and mathematical problems.

Benchmark #3. Know the relationships between units of length in a system of measurement, such as 12 inches equals one foot or 100 centimeters equals one meter.

English Language Arts:

Phonics and Word Recognition Know and apply grade-level phonics and word analysis skills in decoding words.

a.       Identify and know the meaning of the most common prefixes and derivational suffixes.

b.       Decode words with common Latin suffixes.

c.        Decode multisyllable words.

d.       Read grade-appropriate irregularly spelled words, including high-frequency words.


1. Ask and answer questions to demonstrate understanding of a text, referring explicitly to the text as the basis for the answers.  Describe the relationship between a series of historical events, scientific ideas or concepts, or steps in technical procedures in a text, using language that pertains to time, sequence, and cause/effect.  Determine the meaning of general academic and domain-specific words and phrases in a text relevant to a grade 3 topic or subject area.

1. With prompting and support, create an individual or shared multimedia work for a specific purpose (e.g., to create or integrate knowledge, to share experiences or information, to persuade, to entertain, or as artistic expression.)

a. With prompting and support, critique each found image under consideration for use in a multimedia project for its appropriateness to purpose, its effectiveness in conveying the message, and its effect on the intended audience and justify its use in the project.

b. Share the work with an audience.


1. Speak in complete sentences when appropriate to task and situation in order to provide requested detail or clarification. (See grade 3 Language Standards 1 and 3 on page 41-42 for specific expectations.)


Student Misconceptions 
  • As students age, there is a shift from the view that objects and things carry out certain tasks "because they want to" to reasoning that "they need to in order to live." (Driver, R., Squires, A., Rushworth, P., & Wood-Robinson, V. (1994). Making Sense of Secondary Science. New York: Routledge. p. 127.)
  • Students hold a much more restricted meaning of the word animal.  For example, most students list only vertebrates as animals.
  • Students may have difficulty understanding that an organism can be classified as both a bird and an animal.
  • Students often do not recognize that trees, vegetables, and grass are all plants.
  • Some believe that objects that are active are alive, for example fire and clouds; but others think plants and certain animals are nonliving.

Source: NSDL Science Literacy Maps

  • Students may fail to develop a generalization of what a plant is if they are limited in experience to one type of plant. (Keeley, P. (2007) Uncovering Student Ideas in Science.  Vol 2. USA : NSTA Press. p. 95.)


Life science in 3rd grade centers on students learning about the structures and functions of organisms.  The teacher works outdoors with her students and has them keep records in a science notebook.  She also integrates inquiry, cooperative learning and EL strategies.  The teacher also incorporates the MN ELA standards related to using Research to Build and Present Knowledge.

In the spring, Ms. Arthropod puts students into cooperative, multi-ablility groups of three.  They go on a nature walk outside with the purpose of collecting insects.  Students collect insects using their forceps and put them into collecting containers.  When they return to the classroom, they use hand lenses to make observations about what their insects look like and do.  To help her EL students, Ms. Arthropod has a set of flashcards with words and pictures on a ring for her students to use while recording their observations.  Words include verbs such as jump, crawl, smell, see, carry; insect names like ant, spider, mosquito, fly and caterpillar; and common parts such as legs, antennae, head and wings.  Students make a detailed drawing of their insects in their science notebooks, including labeling the parts.  The teacher models inquiry questions such as, "How do long hind legs help the grasshopper?" in order to get students thinking about the function of the various structures of insects.  Still in their cooperative groups, students discuss and record questions about the functions of their insects' parts.  Students then take any questions and research the answers on the internet.  To organize their information, students put their information into an Inspiration Software web which Ms. Arthropod will upload to their class webpage to share with parents and other classes (see below).  Gifted/Talented students can add additional information to the web about if the feature is necessary for growth, reproduction or survival.  To wrap up the activity, Ms. Arthropod uses a sentence frame "my insect uses _____ to ______" to do a quick informal assessment of students' learning.

Example web:

Example of 3rd Grade Science Notebook

Picture used with permission from Alicia Schumacher


Instructional Notes 

Instructional suggestions/options

Include the basic process skills of inquiry in Life Science lessons: observing, communicating, classifying, measuring, predicting, inferring. Fathman, Ann K., & Crowther, David T. (2006). Science for English Language Learners. Arlington, Virginia: NSTA Press.

Access students' prior knowledge related to plants and animals before beginning observations or instructions through graphic organizers such as a KWL.  

Strategically group students during labs to promote academic discussion among all levels of students. 

During students' observations, create word walls of words they come up with and add to it throughout instruction.

The use of science notebooks is valuable for students to record and organize their observations of organisms.  Students should use their science notebook to make scientific drawings of organisms (both animal and plant) and label important structures.  They should make tables and graphs to compare and classify different kinds of organisms (e.g. seeds).  The science notebook is also an opportunity for students to record systematic data over time to use in their analysis of organisms and how they grow and survive.  To see examples of science notebooks, go here

To learn more about the use of science notebooks, see this page. 

Teacher Life Science course on Classifying Living Things including a video for teachers to learn more about teaching Life Science.

Suggested Labs and Activities

Outdoor Observations:

Collect leaves and sort into tree categories. (Fits with Benchmark

Observe organisms (insects, mammals and birds) in the schoolyard over time to allow students to record and analyze how their various structures aid them in growth, survival and reproduction. (Fits with Benchmark

FOSS: Structures of Life

Investigation 1: ORIGIN OF SEEDS

Students conduct a seed hunt by opening fresh fruit and locating the seeds.  They describe and compare seed properties.  Students examine and sort a selection of seeds - bean, pea, sunflower, and corn.  They investigate the effect water has on the seeds by setting up seed sprouters and observing and recording changes over a week.  Students systemically find out how much water lima beans soak up in a day. (Fits with Benchmark

Investigation 2: GROWING FURTHER

Students examine germinated seeds to determine similarities and differences in the way the organisms grow.  They set up a hydroponic garden to observe the life cycle of a bean plant. (Fits with Benchmark by observing structure and function, and Benchmark through comparing and identifying different types of seeds)

Investigation 3: MEET THE CRAYFISH

Students observe and record some of the structures of a crustacean, the crayfish.  They establish a feeding and maintenance schedule for the organisms.  Students investigate crayfish behavior by creating an enriched crayfish habitat.  They map where the crayfish spend their time within their habitat.  Students investigate crayfish territorial behavior. (Fits with Benchmark through observing an organism's habitat and behavior)

Investigations 4 and 5: MEET THE LAND SNAIL or BESS BEETLES

Students become familiar with snail or beetle structures and behaviors and set up an appropriate habitat for the animals.  They compare the structures and behaviors of the snail (a gastropod) or the beetle (an insect) to the crayfish (a crustacean).  They investigate the pulling power of the organisms.  Students plan and conduct their own projects to find out more about the structure and function of animals. (Fits with Benchmark through observing the structure and function of organisms)

**More information can be found here.


Instructional Resources 

Additional resources:

Video Clip: Essential Science for Teachers: Life Science: Session 4. Plant Life Cycles.

This segment focuses on the adaptations of seeds.  AAAS Benchmark: 5D (3-5) #1.  For any particular environment, some kinds of plants and animals survive well, some survive less well, and some cannot survive at all.

Video Clip: Essential Science for Teachers: Life Science: Session 2. Classifying Living Things. 

Children are interviewed in pairs about how freshwater plants and wetland plants are similar and different.  Examples of the plants are present on the tables.  AAAS Benchmark: 5A (K-2) #1.  Some animals and plants are alike in the way they look and in the things they do, and others are very different from one another.

Video Clip: Case Studies in Science Education: Najwa and Pat-Grade 1. 

A class discusses how they can learn about animals and the features of different animals.  They then break into groups to work at different stations.  AAAS Benchmark: 5A (K-2) #2. Plants and animals have features that help them live in different environments.

Lesson Plans

Classification 1: Classification Scheme: See this page.

Purpose: Students will explore the idea that many kinds of living things can be classified in many ways using various features to decide which things belong to which group and that classification schemes will vary with their purpose.

Classification 2: A Touch of Class: See this page.

Purpose: This is the second part of a digital lesson that will allow students to explore the idea that many kinds of living things (e.g. plants and animals) can be classified in many ways using various features to decide which things belong to which group and that classification schemes will vary with their purpose.

Animal Diversity

Purpose: To guide students to explain their observations of animal and plant similarities, diversity, and appropriateness to live in different environments; to show that stories sometimes give plants and animals attributes that they don't really have.  See this page.

New Vocabulary 


  • Behavior: things that animals do.
  • Environment: the surroundings of a plant or animal.
  • Extinct: no longer alive anywhere on earth.
  • Function: how a structure works or how it is used by an animal.
  • Growth: when an organism gets bigger and more complex.
  • Habitat: where an organism naturally lives.
  • Life cycle: the sequence of changes undergone by an organism as it develops from its earliest stage to the same stage in the next generation.
  • Nutrient: a material used by a living organism to help it grow and develop.
  • Organism: any living thing, including plants and animals.
  • Parasite: an organism that lives on or in a plant or animal of a different kind.  The parasite gets nutrients from the other animal or plant.
  • Predator: an animal that hunts and catches other animals for food.
  • Property: something you can observe, like color, texture, or smell.
  • Reproduce: to produce new plants or new animals.
  • Stem: any stalk supporting leaves, flowers, or fruit.
  • Structure: any identifiable part of an organism.
  • Territory: the part of an animal's habitat that it defends against others of its own kind.
  • Thrive: to grow fast and stay healthy. (SS)

(Vocabulary taken from this site.)

Technology Connections 

Inspiration 9.0/Kidspiration

Interactive, digital software to make semantic webs and graphic organizers.

Cross Curricular Connections 

Third grade students will go to the Minneapolis Institute of Art: Connected to Structures of Life Observation in Science.  This project will allow third grade students to make connections between the importance of observation in arts and science.  Third grade student study structures of living things and animal classification as a part of their Minnesota State Science Standards.  Students observe live animals and learn about how form and function are related.  We would like to enhance this aspect of the science curriculum by including an Art Adventure visit from the Minneapolis Institute of the Arts called Amazing Animals in Art and a field trip to see the real animal art pieces that students learn about.


Assessment of Students

Informal assessment options: science notebooks, reflective journals; students create models of organisms and write about their structure and function, produce labeled drawings of plants and animals showing their features.

Is it Living? (Keely, P. (2004) Uncovering Student Ideas in Science. Vol. 1. USA: NSTA Press. pp. 123-130.)  (taxonomic level: synthesis)

Is it a Plant? (Keely, P. (2007) Uncovering Student Ideas in Science. Vol 2. USA: NSTA Press. pp. 93-99.)   (taxonomic level: application)

Multiple Choice: Level 3

Scientists study warblers by placing small metal bands on the birds' legs.  A number is stamped on the band.  This number lets scientists know when and where the birds are banded.

There are many kinds of warblers throughout the world.  One kind of warbler with black-and-white feathers is often seen on tree trunks.  Another kind with golden-colored feathers is often seen in fields.

Which statement best explains how the color of these warblers helps them survive?

A. The color of the feathers helps the birds locate nests.

B. The color of the feathers helps to control the amount of body heat the birds lose.

C. The color of the feathers blends into the birds' surroundings and helps the birds avoid predators.

D. The color of the feathers attracts the kinds of insects the birds like to eat.

Answer: C  (taken from this site)

Multiple Choice: Level 2

Look at the banana plant above.  What part of this plant helps it get the most light?

A. Green fruit

B. A peeling, thick stem

C. Wide, long leaves

D. Brightly colored flowers

Answer: C  (taken from this site)

Multiple Choice: Level 1

A green tree frog lives in a forest.  How does the frog's green color help it to survive?

A. By helping the frog find other frogs.

B. By keeping the frog cool.

C. By making the frog hard to see when sitting on leaves.

D. By allowing the frog to make its own food.

Answer: C  (taken from this site)

Constructed Response: Level 3

Describe at least two characteristics of an animal, a duck in this case, that make it adaptable to its environment.

Answer: Webbed feet for swimming

            Pointed bill for eating grass and small prey

            Wings for flying

            Colors blend into its surroundings

Assessment of Teachers

Do I understand that groups of organisms have different structures that serve different functions (for growth, survival and reproduction) and how they are classified? 

What do I know and need to know about classification of organisms based on their structures? 

What do my students need to know about structures and functions of organisms? 

What do my students need to know about classification?

Essential Questions:

a. How do the characteristics of animals and plants help them survive?

b. How can animals be grouped based on their similarities and differences?

c.  How can plants be grouped based on their similarities and differences?

(from Edina Public Schools, Edina, MN:  GRADE 3 Units & Essential Questions)


At Risk 

Read aloud science trade books (e.g. Chirping Crickets by Melvin Berger) then together as a group talk about structure and function of the animal.  Have students respond by drawing a picture of an animal (or have a drawing already created) from the story and circle or highlight important features of the body.

Some good resources for trade books are www.cde.ca.gov/ci/sc/ll , and annually in the March issues of the National Science Teachers association journals Science and Children, Science Scope, and The Science Teacher">here.

English Language Learners 

Make vocabulary posters of important words (e.g. structure, function, organism, growth, reproduce, habitat, behavior).  Posters should include the word, a definition, a sentence using that word, and a picture.

Extending the Learning 

Students can create an imaginary creature model with imaginary survival features using materials in the classroom (pipe cleaners, egg cartons, etc.).  Students can then write about the features and how they benefit the creature's survival.


Research animals from around the world with which students may not be familiar.  Pick one animal from another country and one from Minnesota (e.g. mouse deer in Laos and white-tailed deer in MN) and make an interactive Venn Diagram showing similarities and differences in their features.  Write a few sentences about why their features might differ and benefit them in their environment.

Special Education 

Have students sort pictures of animal features (e.g. antlers, flippers, antennae, hooves, claws, etc.) into groups and explain orally why they chose those groups.  Or give students categories such as survival, growth, and reproduction and have them sort the pictures. 


Classroom Observation 


Administrators should expect to see students working hands-on with live organisms making observations, classifying, and comparing similarities and differences.


Work with your child at home to observe plants and animals around you and identify what characteristics they have; for example, the family cat has fur, the Christmas tree has needles.  Why do they have these things?  Ask questions about how animals' features are similar or different.