Biology I / The Cytoskeleton
Practice question · Numerical answer

Microtubules are about 25 nm in diameter and microfilaments about 7 nm. How many times wider is a microtubule, to one decimal place?

Hints
  1. Divide the larger diameter by the smaller.
  2. Compute 25 divided by 7.
Show the answer

3.6 (answers within ±0.15 count)

Why

25/7=3.625/7 = 3.6 times wider. The difference matters mechanically: a wider hollow tube is far stiffer in bending, which is why microtubules serve as tracks and spindle fibres while thin actin filaments handle deformation.

Read the lesson: The Cytoskeleton →

Practise The Cytoskeleton

The app has 5 more questions on this lesson, and keeps your place in the course. Biology I is free to start.

More questions on The Cytoskeleton