MS-LS1-6: Photosynthesis and the Flow of Energy
Also called NGSS MS-LS1-6 · Topic: Matter and Energy in Organisms and Ecosystems · Life Science
The Official Wording
Construct a scientific explanation based on evidence for the role of photosynthesis in the cycling of matter and flow of energy into and out of organisms.
Clarification statement: Emphasis is on tracing movement of matter and flow of energy.
Assessment boundary: Assessment does not include the biochemical mechanisms of photosynthesis.
NGSS Lead States, 2013 · Read it on nextgenscience.org · checked October 15, 2026
What MS-LS1-6 Means in Plain English
Students use evidence to explain how photosynthesis brings matter and energy into living things. Plants take in carbon dioxide and water, capture energy from sunlight, and build sugar while releasing oxygen. That sugar becomes food for the plant and for the animals that eat it.
Students trace inputs and outputs, not the chemical steps inside the chloroplast. This builds on 5-LS1-1, where plants get their building material from air and water, and leads to cellular respiration (MS-LS1-7) and matter cycling in ecosystems (MS-LS2-3).
MS-LS1-6 I Can Statements
- I can name what goes into and comes out of photosynthesis.
- I can explain where a plant's food and mass come from.
- I can use evidence to show plants take in carbon dioxide.
MS-LS1-6 Worked Example
A color-change test a class can run with bromothymol blue, elodea sprigs and a desk lamp.
Does a water plant take in carbon dioxide when it has light?
Set It Up: Bromothymol blue solution, a straw, four test tubes with stoppers, two elodea sprigs, aluminum foil and a desk lamp.
- Gently blow through the straw into the blue solution until it turns yellow.Blue to yellow: carbon dioxide added
- Fill four tubes with the yellow solution, add elodea to two, and stopper all four.Two with a plant, two without
- Wrap one plant tube and one empty tube in foil, then set all four under the lamp.A light pair and a dark pair
- Check the colors after 24 hours.Plant in light: blue. The other three: yellow
Only the elodea in light turned the solution back to blue, so it removed carbon dioxide from the water.
Why it works: In light, the plant uses carbon dioxide and water to build sugar, storing the light's energy in that sugar and releasing oxygen.
Common Mistakes with MS-LS1-6
Thinking plants get their food from soil
“A plant's mass comes from the dirt it grows in.”
Try this: Most of a plant's mass is built from carbon dioxide taken from the air, plus water. Soil supplies only small amounts of minerals.
Treating sunlight as matter
“The plant turns sunlight into sugar.”
Try this: Sunlight provides the energy, not the matter. The atoms in sugar come from carbon dioxide and water, and the energy is stored in it.
Forgetting that plants use their food
“Plants only make food, they never use it up.”
Try this: Plants also use cellular respiration, breaking down sugar for energy day and night, which is why the dark tube stayed yellow.
Where MS-LS1-6 Fits
Practice MS-LS1-6
Quick Check
- Where does most of the mass of a tree trunk come from?
- Why did the elodea tube wrapped in foil stay yellow?
- How does energy from the sun end up in a rabbit?