Answer: Svedberg sedimentation unit.
- A Its size in nanometres
- B Svedberg sedimentation unit
- C The number of subunits
- D Its total surface area
Correct answer: B. Svedberg sedimentation unit
Explanation: 'S' is the Svedberg unit, a measure of sedimentation rate in a centrifuge. Because it depends on shape and mass, the values are not additive (50S + 30S = 70S).
Animal cell structure with major organelles labeled. Image: LadyofHats (Mariana Ruiz), Public Domain, via Wikimedia Commons.
Concept context
Cell theory, prokaryotic vs eukaryotic cells, organelles and their functions. Foundation of all biology.