🔬 Cell Theory

Chapter: The Cell · Level ★☆☆ · Time: 15 min

SCORE___ / 20

NameClassDate

After this worksheet you can

State the 3 principlesCompare prokaryote/eukaryoteCompare microscopy typesName the key scientists

📚 Quick Recap

🎯 What you'll practice: The three cell theory principles, prokaryote vs eukaryote, and microscopy resolution.

🧮 Section B · Problem Solving ● INTERMEDIATE 2 + 3×3 = 11

5Eukaryotic cells are typically –100 µm in size.

6TEM reveals structure.

7Name the three principles of cell theory.

8Give one example organism for prokaryote and one for eukaryote.

9Why is the electron microscope's resolution described as "1000x better" than the light microscope's?

🚀 Section C · Challenge ● CHALLENGE 5

10Explain why "all cells arise from pre-existing cells" was a significant scientific claim in 1855 — what alternative idea did it rule out?

💭 Reflection — the most useful thing I learned:

A ___/4 B ___/11 C ___/5 Total ___/20 Teacher's Signature Parent's Signature

✂ answer key — fold or cut before handing out

1-B 2-B 3-C 4-B | 5 = 10 6 = internal 7 = all organisms are composed of cells; the cell is the basic unit of life; all cells arise from pre-existing cells 8 = e.g. bacteria (prokaryote), human/plant cell (eukaryote) 9 = because 0.2nm is 1000 times smaller than 0.2µm (1µm = 1000nm), meaning the electron microscope can distinguish objects 1000 times closer together than a light microscope can | 10 = It directly refuted the competing 19th-century idea of spontaneous generation — that living cells could arise on their own from non-living matter — establishing instead that cell division from an existing cell is the only way new cells are formed, a foundational principle for understanding growth, reproduction, and disease.

📄 Need offline practice?Print this worksheet or open the one-page cheat sheet.

🗒 Cheat Sheet

🧠 Section A · Concept Check ● BEGINNER 4 × 1 = 4

🧮 Section B · Problem Solving ● INTERMEDIATE 2 + 3×3 = 11

🚀 Section C · Challenge ● CHALLENGE 5