Hint: The nucleolus is the different format existing in the nucleus of eukaryotic cells. Mainly, it contributes in developing the ribosomes, substitution of transfer RNA and grasping cellular anxiety.
Let us analyse the given options to find out the correct option.
Option A: Nucleolus in a eukaryotic cell is not non living, they are living. This is an incorrect option.
Option B: Nucleolus in a eukaryotic cell is not noticeable in metaphase, only evident in prophase. This is an incorrect option.
Option C: Nucleolus in eukaryotic cells is not bounded by a membrane. This is an incorrect option.
Option D: The nucleolus is the biggest structure in the nucleus of eukaryotic cells. It mainly fulfills as the site of ribosome synthesis and committee (packaging of rRNA and proteins). Nucleolus also has other crucial purposes like the assembly of sight recognition atoms and fiddling a part in the cell's reaction to stress. The nucleolus is created by proteins and RNA and shapes around particular chromosomal areas. Malfunction of nucleolus can be the reason for various human diseases. This is the correct option.
The nucleolus is a vibrant membrane-less configuration whose main function is ribosome biogenesis and ribosomal RNA production.
Hence, the correct answer is option (D)
Note: The nucleolus is contemplated as the brain of the nucleus, encircling almost 25% quantity of the nucleus. Primarily, it seizes part in the creation of subunits that unifies to shape ribosomes. Hence, nucleolus plays a crucial role in the synthesis of proteins and in the creation of ribosomes in eukaryotic cells.