Students who demonstrate understanding can: Conduct an investigation to provide evidence that living things are made of cells; either one cell or many different numbers and types of cells.
Clarification statement: Emphasis is on developing evidence that living things are made of cells, distinguishing between living and non-living things, and understanding that living things may be made of one cell or many and varied cells.
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
Every organism on Earth, from a bacterium to a blue whale, is built from cells. Middle schoolers are expected to gather that evidence for themselves rather than simply being told it. They look at onion skin, cheek cells, pond water and plant leaves under a microscope, and they notice that every living sample is made of small, bounded units, while samples such as sand, cotton thread or a crystal of salt are not.
The investigation should lead students to two conclusions. First, cells are a defining feature of life: anything alive is made of at least one cell. Second, organisms differ in how many cells they have and what kinds. A paramecium or a yeast cell is a complete organism on its own, while a human body contains trillions of cells of many specialized types, such as nerve, muscle and blood cells.
Students also practice the skills of a careful investigation: preparing a slide, focusing from low to high power, drawing what they actually see, and recording magnification. The goal is evidence-based reasoning, so a strong answer ties each claim to an observation.
Some students picture cells as a body-only idea. Showing onion skin, a leaf and mold side by side makes it clear that plants and fungi are made of cells too.
Students may think an organism has to be large or have organs to count as alive. A moving, feeding paramecium under the microscope is strong evidence that one cell can carry out every life function.
Cotton, paper and cooked food came from organisms, yet their cells are dead or broken down. Discuss the difference between being made of cells and being alive right now.
An elephant is larger than a mouse because it has many more cells, not because its cells are giant. Most animal cells are similar in size whatever the size of the animal.
A student views three samples under a microscope at 100x. Sample A shows many small boxes with dark dots inside. Sample B shows sharp-edged cubes with no inner structure. Sample C shows one oval shape that moves and has hair-like structures around its edge. Which samples are or were living, and what is the evidence?
Answer: A (multicellular) and C (unicellular) are from living things because they are made of cells; B is a nonliving crystal with no cells.
Run this as a genuine investigation: give groups a mixed set of labeled and unlabeled slides and ask them to sort living from nonliving before revealing the answers. Insist on drawings that show only what is visible, with the total magnification written next to each. Comparing a prepared slide of a multicellular leaf with a drop of pond water sets up the unicellular versus multicellular discussion naturally.
Assessment items usually present microscope images or data tables and ask students to use them as evidence, so practice writing claim, evidence and reasoning sentences from images rather than recalling vocabulary alone.
Original questions written for this standard. Choose an option or type your answer, then press Check. Every question has a worked explanation.
Answer: B) It is made of one or more cells
Being made of cells is a feature of all living things. Color, texture and dissolving do not tell living from nonliving.
Answer: C) It is a unicellular organism that carries out all life functions in one cell
A unicellular organism is a complete living thing made of a single cell, which takes in food, gets rid of waste and reproduces.
Answer: multicellular (also accepted: multi-cellular)
Multicellular organisms, such as humans and oak trees, are made of many cells, often of many different types.
Answer: A) Salt is not made of cells, so it is not a living thing
Salt is a crystal. It has no cell boundary or contents, which fits a nonliving material.
Answer: B) Different cells do different jobs in a multicellular organism
In multicellular organisms, cells are specialized: nerve cells carry signals and muscle cells contract.
Answer: microscope (also accepted: a microscope, light microscope)
Most cells are far too small to see without magnification, so a microscope is needed.
A full lesson with slides, activities and an exit ticket on living things are made of cells, pitched to grades 6-8 and editable in PowerPoint or Google Slides.
Make a lesson βA printable, differentiated worksheet on MS-LS1-1 with an answer key, ready in about a minute.
Make a worksheet βTurn living things are made of cells into a quiz students answer online that marks itself, with a class summary for you.
Build a test βThey conduct an investigation, usually with microscopes, to collect evidence that living things are made of cells, comparing living and nonliving samples and unicellular and multicellular organisms.
No. The focus is evidence that organisms are made of cells. The functions of cell parts belong to MS-LS1-2.