List the name of the structure indicated by the arrow in the image
The Correct Answer and Explanation is:
The structure indicated by the arrow in the image is the nucleolus.
The nucleolus is a dense, spherical structure found within the nucleus of eukaryotic cells. It is not membrane-bound but consists of RNA and proteins. The primary function of the nucleolus is the synthesis and assembly of ribosomal RNA (rRNA) and the formation of ribosomal subunits. These subunits are then exported from the nucleolus to the cytoplasm, where they combine to form functional ribosomes. Ribosomes are essential for protein synthesis in cells.
The nucleolus forms around specific regions of chromosomes known as nucleolar organizer regions (NORs), which are rich in rRNA genes. The process that occurs within the nucleolus includes transcription of rRNA, modification, and assembly with ribosomal proteins to form large and small ribosomal subunits. These subunits are essential for translating messenger RNA (mRNA) into proteins.
In addition to its primary role in ribosome production, the nucleolus also participates in various cellular processes such as cell cycle regulation and stress responses. Its size and prominence can vary depending on the cell’s activity level; for example, cells that are actively producing proteins often have larger nucleoli due to the higher demand for ribosomes.
In summary, the nucleolus is a vital structure within the nucleus, dedicated to producing ribosomes, a fundamental component necessary for protein synthesis in cells.
