Cells Under the Microscope
Understand that all living organisms are made of cells and use a light microscope to observe, interpret, and record cell structure
What a learner can do afterwards
- States that all living things are made of cells
- Prepares or examines a slide of cells (e.g. onion skin, cheek cells) under a microscope
- Draws and labels a diagram of cells observed
- Identifies nucleus, cytoplasm, and cell membrane in a microscope image
The lesson
Every living thing you have ever seen, a tree, a dog, or you, is built from cells. A cell is the smallest unit that is still alive. Most cells are far too small to see with your eyes alone, so scientists use a microscope to make them big enough to study.
To see cells, you peel a thin, see-through layer from the inside of an onion, or gently scrape the inside of your cheek. You place that layer on a glass slide, add a drop of stain to make the parts easier to see, then lower a thin glass square called a coverslip on top.
Zara places onion skin on a slide and looks through the microscope. She sees rows of clear, brick-shaped boxes. Inside each box she spots a small dark circle. That dark circle is the nucleus, the part that controls the cell.
Look for three parts every time: the cell membrane (the thin edge around each cell), the cytoplasm (the jelly-like fill inside), and the nucleus (the dark round spot that controls the cell).
All living things are built from cells, and a microscope lets you see each one's membrane, cytoplasm, and nucleus.
Watch it
Where it sits
Learn first
Nothing; this is a starting point.
Where this leads
Jobs that lean on this skill. Follow one to see everything it is built on.
8 questions wait behind this lesson, each with its answer explained. Every answer feeds the sky: stars light as they are learned, and dim when it is time to come back.