HS-LS1-2: Modeling Body Systems from Cells to Organs
Also called NGSS HS-LS1-2 · Topic: Structure and Function · Life Science
The Official Wording
Develop and use a model to illustrate the hierarchical organization of interacting systems that provide specific functions within multicellular organisms.
Clarification statement: Emphasis is on functions at the organism system level such as nutrient uptake, water delivery, and organism movement in response to neural stimuli. An example of an interacting system could be an artery depending on the proper function of elastic tissue and smooth muscle to regulate and deliver the proper amount of blood within the circulatory system.
Assessment boundary: Assessment does not include interactions and functions at the molecular or chemical reaction level.
NGSS Lead States, 2013 · Read it on nextgenscience.org · checked October 15, 2026
What HS-LS1-2 Means in Plain English
Students build and use a model of how a body is organized in levels, from cells to tissues to organs to organ systems, and how those levels depend on each other. A wing that bends, for example, needs muscle, tendon, bone, nerve and blood vessel working together.
The model stays at the level of tissues, organs and systems, so the chemistry inside cells is not part of it. It builds on MS-LS1-3 and leads to HS-LS1-3, where these systems respond to change and keep the body steady.
HS-LS1-2 I Can Statements
- I can name the levels of organization from cell to organ system.
- I can model how muscles, bones and nerves work together to move a limb.
- I can predict what fails when one tissue in a system is damaged.
HS-LS1-2 Worked Example
A dissection that turns a raw chicken wing into a working model of the muscular, skeletal, nervous and circulatory systems.
Which tissues have to work together for a chicken wing to bend and straighten?
Set It Up: Raw chicken wings from the grocery store, dissecting trays, scissors, probes, gloves and a sketch sheet for labels.
- Peel back the skin and sketch what sits underneath.Pink muscle bundles in a thin clear membrane
- Pull one muscle gently with a probe and watch the joint.The wing tip bends
- Follow that muscle to the shiny white cord that anchors it to bone.Tendon joins muscle to bone
- Look along the bone for thin white threads and small red tubes.Nerves and blood vessels beside the muscle
- Label each part on the sketch with its tissue type and its system.Muscle, connective, nervous, blood
Bending the wing took muscle to pull, tendon to pass the pull along, bone to act as a lever, and nerves and blood vessels to control and feed the muscle.
Why it works: Organs are built from several tissues, and each organ system works only because it depends on parts from other systems.
Common Mistakes with HS-LS1-2
Treating systems as separate
“The muscular system moves the wing by itself”
Try this: Trace each movement back through several systems. Muscles need nerve signals to contract and blood to deliver oxygen and sugar for energy.
Mixing up tissues and organs
“Muscle tissue is an organ”
Try this: A tissue is a group of similar cells doing one job. An organ, like the heart, is built from several kinds of tissue.
Confusing tendons and ligaments
“The white cord holding bone to bone is a tendon”
Try this: Tendons connect muscle to bone so a pull moves the skeleton. Ligaments connect bone to bone and hold the joint together.
Where HS-LS1-2 Fits
Practice HS-LS1-2
Quick Check
- Is the heart a tissue or an organ? Why?
- What would happen to arm movement if the nerve to a muscle were cut?
- Name two systems the circulatory system supports during exercise.