Table of Content
The nucleus is a dense and most significant component of the cell. Animal cell nucleus has a lot of functions like controlling all the cellular activities and carrying the hereditary information of the cell. It is found in both plant and animal cell. In 1831, Robert Brown first discovered the nucleus in an orchid cell.
All the eukaryotic animal cells have a true nucleus except mature mammalian RBCs. The prokaryotes have incipient nucleus called as nucleoid or genophore or prokaryon.
The nucleus is generally located at the center of the animal cell. It is mostly spherical in shape. However, its shape may be cuboidal, ellipsoidal, discoidal or irregular. Size of the animal cell nucleus varies between 5 to 25 micrometers, depending upon the size of the cell and age of nucleus. Most of the animal cells have a single nucleus while some cells like liver cells, Paramecium, etc have two nuclei. Some animal cells like osteoblasts even have multiple nuclei.
Structure of Animal Cell Nucleus
Ultrastructure of animal cell nucleus shows the following four components:
- Nuclear membrane : It is the thin double layered porous outer envelope of the nucleus. Hence, it regulates nucleo-cytoplasmic interactions and acts as a selectively permeable membrane.
- Nucleoplasm : It is a transparent, semi-fluid homogenous and gel-like substance present inside nuclear membrane. Nucleoplasm is chemically composed of lipids, water, fat, mRNA, etc. It acts as a nuclear skeleton and helps in maintaining the shape of the nucleus.
- Chromatin fiber : It is a numerous, dark staining, thread like structure in the nucleoplasm. They are coiled upon themselves, forming a mass of chromatin reticulum. It contains DNA which acts as genetic material.
- Nuclelous :The animal cell nucleus contains one or more small dense rounded body called nucleolus. Its main function is the biogenesis of the r-RNA.
Function of Animal Cell Nucleus
- The nucleus controls all the cellular activities in an animal cell.
- Synthesis of r-RNA occurs in the nucleolus of the nucleus.
- Nucleus stores hereditary information in chromosomes which is essential for continuity of species. So, nucleus transmits all the hereditary information from parents to their offspring.
- All instructions for development, metabolism, and behavior are in the chromosome of the nucleus.
- Nucleus helps in the production of ribosomes.
- Nucleoplasm contains many essential enzymes necessary for biochemical activities of the cell.
- During the division of an animal cell, nucleolus (with centriole) produces spindle fibers.
- Nucleus controls cellular differentiation.
- It includes genetic variation which helps in organic evolution.
- The nucleus directs all cell organelles for their specific function.
- Nucleus controls and monitors cell division.
Finally, we have come to an end. If you would like us to suggest and inspire us for a better article, you may comment below……..