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Marlow Works

AP Biology / Unit 2

Unit 2 · 10–13%

Cells

Membranes make insides. Organelles divide the labor.

Start first lessonUnit practice

Topics

  • Prokaryotic and eukaryotic cells
  • Organelles
  • Membrane structure
  • Transport

Lessons

Key terms

Original practice

Marlow Works questions. If this unit does not have its own items yet, you will see other questions from the same course.

1 of 2Membranes · medium · multiple choice

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.

Review checklist

  1. 01Compare a prokaryotic cell and a eukaryotic cell with more than “nucleus.”
  2. 02Name one job for mitochondria, chloroplasts, ribosomes, and the Golgi.
  3. 03Predict the direction of water movement in a simple tonicity setup.

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 source

  • Reference 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