![]() It is synthesized from DNA and is piled up in the nucleolus. It is also present in some amounts in the ribosomes of nucleus, chromatin, and nucleolus. Nucleic acid contains sugar, nitrogenous bases, phosphate, and is a very complex organic acid.ĭNA (Deoxyribonucleic acid) especially found in the cytoplasm in soluble form and is called soluble RNA. It is primarily nucleoprotein, made up of nucleic acid and basic protein histone. At the time of cell division, the chromatin threads isolated from one another become thicker or massive and smaller and are now termed as chromosomes. Chromatin threads are associated with one another and form a network called chromatin reticulum. On the other hand, euchromatin is a mild, less condensed organization of chromatin, which is found amply in a transcribing cell. The heterochromatin is a highly condensed, transcriptionally inactive form mostly present adjoining to the nuclear membrane. The chromatin is classified further into heterochromatin and euchromatin based on the functions. The nuclear membrane is made up of lipoproteins, perinuclear space, pores, annuli material, an inner dense lamella.Ĭhromosomes are present in the form of strings of DNA and protein molecules called chromatin. Such nuclear pores are the sites for the exchange of large molecules between the nucleus and cytoplasm. The nucleus gets through the remaining of the cell or the cytoplasm through several openings called nuclear pores. A liquid-filled space or perinuclear space is present between the two layers of a nuclear membrane. The nuclear envelope is connected with the endoplasmic reticulum in such a way that the internal compartment of the nuclear envelope continuous with the lumen of the endoplasmic reticulum. The outer layer of the membrane is combined with the endoplasmic reticulum. ![]() The nuclear membrane is a double-layered system that encloses the elements of the nucleus. Nuclear membrane or envelope or karyotheca The main components of the nuclear structure are discussed below. ![]() The nucleus is similar to the brain in its functions of coordinating all the cell activities. The DNA controls the form, function, and growth of the cell. The envelope helps to maintain the shape of the nucleus and assists in coordinating the flow of the molecules into and out of the nucleus through nuclear pores. Like the cell membrane, the nuclear envelope consists of phospholipids that form a lipid bilayer. The nuclear membrane separates the constituents of the nucleus from the cytoplasm. Nucleoplasm, also called karyoplasm, is the matrix present inside the nucleus. The cell nucleus consists of a nuclear membrane, called the nuclear envelope, nucleoplasm, nucleolus, and chromosomes. Unlike mammalian red blood cells, those of other vertebrates still contain nuclei. Antonie van Leeuwenhoek observes a ‘lumen’, in the nucleus, in the red blood cells of salmon. The nucleus was the first organelle to be discovered or detected. The nucleus is detached from the rest of the cell or the cytoplasm by a nuclear membrane. Some are multinucleate it means it consists of two or more nuclei, for example, slime mould. However, some eukaryotic cells enucleate cells (without a nucleus) for example red blood cells. In general, a eukaryotic cell has the only nucleus. The nucleus is the most prominent organelle as compared to other cell organelles, which account for about 10 percent of the volume of the cell. The structure of the nucleus includes nuclear membrane, chromosomes, nucleoplasm, and nucleolus. It is also responsible for the coordination of genes and gene expression. The nucleus is the control centre of eukaryotic cells. The nucleus is a spherical-shaped organelle that is present in every eukaryotic cell. Likewise, in the plant cell, the nucleus is located more on the periphery due to the large water-filled vacuole in the center of the cell. In an animal cell, the nucleus is located in the central place of the cell. ![]() The nucleus is an organelle that consists of the genetic information for that organism. Likewise, Eukaryotic cells all have their DNA enclosed in the nucleus. The prokaryotes have no nucleolus- the DNA is in the cytoplasm, it can form small circular strands of DNA called plasmids. There are two types of cells one is prokaryotic (bacteria) and the other is eukaryotic (plant, animal, fungi). The Cell provides a structure for the body, takes in nutrients from food and carry out important functions. Cells are the fundamental or key structure of all living organisms. The human body consists of trillions of cells, all with their own particular function. The study of cells is called cell biology. Cells are called the building blocks of life. The cell is the basic and structural, functional, and biological unit of all known living organisms.
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