volume_mute
What is the conspicuous dark area within the nucleus that contains a high concentration of ribonucleic acid and protein?
publish date: 2026/06/15 06:27:53.750691 UTC
volume_mute
When a cell is not dividing, there is a conspicuous dark area visible within the nucleus.
What is this structure called, and what does it contain?
Correct Answer
nucleolus
Explanation
The nucleolus is a dark, dense area within the nucleus that contains a high concentration of ribonucleic acid (RNA) and protein. It is the site where ribosome production occurs. During mitosis, when chromosomes condense, the nucleolus disappears and ribosome production ceases.
Reference
Biology: A Self-Teaching Guide