Unit 02 · Cells & Their Structures
Every living thing is made of cells — the tiny building blocks of life. In this unit you’ll learn the cell theory, compare plant and animal cells, and find out what each part does, from the cell membrane to the nucleus to the mitochondria. Best of all, you’ll use a real microscope to see cells for yourself. Mastery means you can spot cell parts under the lens and explain the job each one does.
| Criterion | Not yet | Approaching | Mastered |
|---|---|---|---|
| Cells & cell theory | Thinks only some living things, like animals, are made of cells. | Says living things are made of cells but can’t explain the cell theory. | Explains that all living things are made of cells and states the cell theory in their own words. |
| Plant vs. animal cells | Can’t tell a plant cell from an animal cell. | Names a difference or two but mixes up which cell has what. | Compares plant and animal cells and explains why plant cells have a cell wall and chloroplasts. |
| Cell parts & their jobs | Can name one or two parts but not what they do. | Lists the parts but matches only some to their jobs. | Names the main parts — cell membrane, nucleus, cytoplasm, mitochondria, and more — and explains the job of each. |
| Cells as living systems | Thinks a cell is just a blob with no working parts. | Knows cells are busy but can’t connect a part to a life process. | Explains how the parts work together so the cell can get energy, grow, and stay alive. |
| Lab technique (using a microscope) | Can’t focus the microscope or makes a messy slide. | Gets an image but struggles to focus clearly or center the sample. | Makes a clean slide of onion-skin, cheek, or pond-water cells, focuses on both powers, and sketches what they see with labels. |
| Integration (cross-domain) | Treats the science as isolated facts; makes no cross-domain connection. | Names a link to history, reading, or writing but cannot defend why it matters. | Connects the unit to its anchor across History · Reading · Writing (plus chosen electives) and defends why the connection matters. |
“This is a plant cell — I can see the cell wall and the green chloroplasts, and animal cells don’t have those. The nucleus is the control center, and the mitochondria are where the cell gets its energy. I found them by focusing on low power first, then switching to high.”
“It’s a cell, I think. There’s a round thing in the middle. I couldn’t really get it in focus.”
You demonstrate this unit at the microscope — making your own slides of onion-skin, cheek, and pond-water cells, then explaining what each part does aloud, not on a multiple-choice test. A criterion counts as mastered only when you can both find the cells under the lens and explain the biology behind what you see. Mastery is demonstrated, not awarded.
A 5-page clipboard packet — unit overview, key terms, the mastery rubric, anchor examples, and a score sheet you can print and grade against.