4-LS1-1: Plant and Animal Structures
Also called NGSS 4-LS1-1 · Topic: Structure, Function, and Information Processing · Life Science
The Official Wording
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.
NGSS Lead States, 2013 · Read it on nextgenscience.org · checked October 15, 2026
What 4-LS1-1 Means in Plain English
Fourth graders make an argument, backed by evidence, that the parts of living things have jobs. Outside parts like thorns, petals and skin and inside parts like the stomach, heart and lungs help a plant or animal stay alive, grow, act and have young.
Students study parts big enough to see without a microscope, so cells wait until middle school (MS-LS1-1). It builds on 1-LS1-1, where children copy plant and animal parts to solve problems, and leads to body systems in middle school (MS-LS1-3).
4-LS1-1 I Can Statements
- I can name a plant part and the job it does.
- I can name an inside and an outside animal part and their jobs.
- I can use evidence to argue how a part helps survival.
4-LS1-1 Worked Example
A stem test a class can set up one afternoon and check the next morning, with celery and food coloring.
Does a plant's stem carry water up to its leaves?
Set It Up: Two fresh celery stalks with leaves, two clear cups of water, blue food coloring and a hand lens.
- Add 10 drops of food coloring to one cup and leave the other plain.Blue cup, plain cup
- Trim the bottom of each stalk and stand one in each cup.Both stalks upright
- Leave them overnight, then look at the leaves.Blue-tinted leaves only in the colored cup
- Cut both stalks across and look at the cut ends with the hand lens.A row of blue dots near the outer edge
Blue color traveled up through tubes in the stem to the leaves, but only in the stalk standing in colored water.
Why it works: A stem has tubes that carry water from the roots to the leaves, and that structure helps the plant survive and grow.
Common Mistakes with 4-LS1-1
Making a claim without evidence
“Stems hold water because they just do.”
Try this: Back each claim with something you saw, like the blue dots in the cut stem, then explain how that part helps the plant.
Forgetting inside parts
Listing only fur, claws and tails for an animal
Try this: Include parts you cannot see from outside. A heart pumps blood and lungs take in air, and both keep the animal alive.
Thinking flowers are just decoration
“Petals are there to look pretty.”
Try this: Bright petals attract bees and other pollinators, which carry pollen between flowers so the plant can make seeds.
Where 4-LS1-1 Fits
Practice 4-LS1-1
Quick Check
- How do thorns help a rose survive?
- What jobs do roots do?
- Name an inside part of an animal and its job.