Lesson
Rooms inside a living box
Eukaryotic organelles divide labor; prokaryotes do a lot with less interior drywall.
Learning goals
- Contrast prokaryotic and eukaryotic organization.
- Assign a function to major organelles in a short scenario.
Explanation
All cells have a membrane, cytoplasm, and ribosomes, and they use DNA. Prokaryotic cells lack a nucleus and membrane-bound organelles. Eukaryotic cells wrap DNA in a nucleus and split jobs among compartments. That split lets a cell digest, package, and make ATP without those processes colliding.
Mitochondria transform energy. Chloroplasts capture light energy in photosynthetic eukaryotes. The endomembrane system—ER, Golgi, vesicles—builds and ships proteins and lipids. Ribosomes are the actual peptide factories, whether free or bound.
Key terms
- Organelle. A specialized structure inside a eukaryotic cell that performs a particular job.
- Ribosome. A structure that builds proteins from an RNA message.
Common mistakes
- Saying prokaryotes have no DNA or no ribosomes.
- Treating the nucleus as the only difference that matters.
Practice
Original Marlow Works items. Check the answer explanation after you try.
A cell’s surface-area-to-volume ratio is important because it affects:
Original Marlow Works item — not a College Board question.
Take your time—this is practice, not a test.
Answer explanation
Why does a very large cell run into a surface-area problem?
Answer. Volume grows faster than surface, so membrane transport cannot keep up with the cell’s needs.
Exchange happens at the surface; living work happens in the volume.
Related resources
External links with reuse status. Marlow Works is independent and does not copy restricted exam or textbook material.
Official / link only
AP Biology course page
Official eight-unit framework, science practices, and lab resources.
College Board · All rights reserved · accessed 2026-10-01
Open sourceReference only — do not copy
OpenStax Biology 2e
Biology reference with commercial-use restrictions on the current publisher page.
OpenStax · CC BY-NC-SA 4.0 with additional restrictions · accessed 2026-10-01
Link only unless permission is obtained.
Open source