Students who demonstrate understanding can: Develop and use a model to describe the function of a cell as a whole and ways the parts of cells contribute to the function.
Clarification statement: Emphasis is on the cell functioning as a whole system and the primary role of identified parts of the cell, specifically the nucleus, chloroplasts, mitochondria, cell membrane, and cell wall.
Assessment boundary: Assessment of organelle structure/function relationships is limited to the cell wall and cell membrane. Assessment of the function of the other organelles is limited to their relationship to the whole cell. Assessment does not include the biochemical function of cells or cell parts.
Official wording from the Next Generation Science Standards (NGSS Lead States, 2013). NGSS is a registered trademark of WestEd. Neither WestEd nor the lead states and partners that developed the NGSS were involved in the production of this page, and they do not endorse it. View on nextgenscience.org
A cell behaves like a small, busy system in which each part supports the survival of the whole. Students build and use models, such as labeled diagrams, analogies or physical models, to show how the nucleus, cell membrane, cell wall, mitochondria and chloroplasts each contribute. The nucleus holds the genetic instructions that direct the cell's activities. The cell membrane controls what enters and leaves. Mitochondria release usable energy from food, and chloroplasts in plant cells capture light energy to make food. The cell wall gives plant cells extra support and shape.
Notice that the expectation is about the cell working as a whole. Students are not memorizing detailed chemistry inside each organelle. Instead they explain, for example, what would happen to the whole cell if its membrane stopped controlling entry and exit, or why a plant cell can make its own food while an animal cell cannot.
Comparing plant and animal cells is a natural part of this work, since the cell wall and chloroplasts appear in plant cells but not animal cells, and those differences connect directly to how each organism lives.
Many students assume chloroplasts replace mitochondria in plants. Plant cells have both: chloroplasts make food and mitochondria release energy from that food.
Plant cells have a membrane inside the wall. The wall gives rigid support, while the membrane controls which substances move in and out.
The brain analogy can mislead. The nucleus holds the instructions, but the other parts carry out the work, and the cell needs all of them to survive.
Textbook diagrams make cells look like flat outlines. Remind students that cells are three-dimensional and filled with cytoplasm where many activities happen.
Use a factory model to explain how a plant leaf cell keeps itself alive. Include at least four cell parts and what would go wrong if the membrane failed.
Answer: Each part does a different job, and the cell survives only because the parts work together; losing the membrane would break the control of what enters and leaves, so the cell would die.
Have students compare a microscope image of Elodea or onion cells with a cheek cell, then build their own analogy model and present its limits as well as its strengths. Asking where an analogy breaks down is a quick way to check understanding beyond labels.
The assessment boundary limits structure-function questions to the cell wall and membrane; for the other parts, questions focus on how each one supports the whole cell. Keep the chemistry of respiration and photosynthesis for later standards.
Original questions written for this standard. Choose an option or type your answer, then press Check. Every question has a worked explanation.
Answer: A) Cell membrane
The cell membrane is selectively permeable, letting some materials in and out while blocking others. The cell wall supports but does not control entry.
Answer: D) Plant cell
Cell walls and chloroplasts are found in plant cells, not animal cells.
Answer: mitochondria (also accepted: mitochondrion, the mitochondria)
Mitochondria release usable energy from sugar for the cell's activities.
Answer: B) They have both chloroplasts and mitochondria
Plant cells make food in chloroplasts and release energy from it in mitochondria, so they need both.
Answer: nucleus (also accepted: the nucleus)
The nucleus holds the genetic material (DNA) that controls the cell's activities.
Answer: D) It could no longer make its own food
Chloroplasts capture light energy to make sugar. Without them, the cell cannot make food.
Develop and use a model to illustrate the hierarchical organization of interacting systems that provide specific functions within multicellular organisms.
A full lesson with slides, activities and an exit ticket on how cell parts work together, pitched to grades 6-8 and editable in PowerPoint or Google Slides.
Make a lesson βA printable, differentiated worksheet on MS-LS1-2 with an answer key, ready in about a minute.
Make a worksheet βTurn how cell parts work together into a quiz students answer online that marks itself, with a class summary for you.
Build a test βThe clarification statement lists the nucleus, chloroplasts, mitochondria, cell membrane and cell wall.
No. The assessment boundary excludes the biochemical function of cells and cell parts; the focus is how each part helps the whole cell function.