Question

Nucleosomes and their linker DNA are coiled into a helix to produce a 30 nm wide fibre callwd a solenoid. This has about six nucleosomes per turn of the helix, 40000 nm of DNA are packed into a 1 micrometer lenght of this solenoid. What is the packing ratio of 30 nm fibres? The answer is 40 as in 40000 ÷ 1000 since 1 micrometer=1000 nm. But can someone explain why this answer since it is asking about the 30 nm wide fibre. Use baby words please.

Answer 1

The question is asking about the packing ratio in terms of \(length\), 40000 nm into 1 \(\mu m\), not the width of structure.