On this page, we found out why the DNA that contains part of a bacterium is called a nucleoid and not a nucleus. We have elaborated this by using comparison tables, graphics and images.

Why is the DNA containing part of a bacterium called a nucleoid and not a nucleus?
As a Life Sciences student, you should understand the following about nucleoids and nucleus:
- The first reason is that the nucleoid does not have a protective membrane like the nucleus in advanced cells.
- The second reason is that the nucleoid is simply a compact region where DNA is loosely packed. On the other hand, the nucleus has compartments and systems to organise DNA.
- The third reason is that In the nucleus, DNA is wrapped around the proteins. While in the nucleoid, there are no proteins, so the DNA is packed loosely.

The difference between nucleoid and nucleus can be elaborated in the table below:
Feature | Nucleus | Nucleoid |
---|---|---|
Membrane | Has a protective membrane | No membrane, DNA floats freely |
Location | Found in eukaryotic cells | Found in prokaryotic cells (bacteria) |
Organisation | Highly organised with compartments | Simple and loosely packed |
DNA Packing | DNA wrapped around histone proteins | No histones, DNA packed loosely |
Shape of DNA | Linear DNA (in chromosomes) | Circular DNA |
Size | Larger and takes more space | Smaller and takes less space |
Transcription | Happens inside the nucleus | Happens in the same area as translation |
Complexity | Complex with multiple functions | Simple and only focuses on storing DNA |
Watch this video for further understanding