Nucleus - All information by helpcbsenotes.
Here simple notes are provided related to the nucleus chapter of class 9 "fundamental unit of life of biology". You can use this note for your student and if you are student then you can take quick revision of nucleus. So, let's know about Nucleus and structure of nucleus.
Nucleus
- It is a spherical dense and protoplasmic body found in cytoplasm of the cell.
- it is centrally located in animal and plant cell but in mature plant cell due to the formation of a large centre vacoule in peripheral region of the cell.
- Some cell are unucleated for example red blood cell but some are multinucleated example - paramecium.
Structure of nucleus
1. Nuclear membrane
There are following part of the nucleus
Nuclear membrane.
- it is a double layer membrane which bound nucleus.
- Nucleus membrane has pore that allow the transfer of material in and out of the nucleus these force is know as nuclear force.
2. Nucleoplasm
- The nucleus membrane in closed space which is filled with liquid called nucleoplasm.
- It is a colourness dense liquid in which the chromatin material are present.
3. Nucleolus
- It is dense and spherical structure present in nucleus.
- It is also called brain of nucleus.
- It comprises 25% of the volume of nucleus.
- It consist of Protein and RNA.
- Nucleolus is also called "Factory of ribosomes" because it play an important role in protein synthesis by producing ribosomes.
4. Chromatin material
- Chromatin is thread like material present in the nucleus.
- Chromatin made up of DNA and protein.
- It organise itself and condensed to from thick road like structure known as chromosomes when cell is dividing.
5. Chromosomes
- They are present in nucleus and bounded by a membrane.
- Chromosomes are made up of DNA and protein and appear rod like in shape.
- DNA molecule store all information which is necessary for cell function, grow and reproduce in the form of gene.
- Each chromosome consists of two similar thread chromatids.
- the point of attachment of chromatid is called centromere.
- The elongated part of either side of Centromere are called arms.
6. Function of nucleus.
1. Genetic information
It is the most important function of nucleus to store genetic information.
2. Controlling centre
It control metabolic activities of cell.
3. Cell division
During division nucleus also divide with cytoplasm of cell.
4. Synthesis of ribosomes
The nucleolus of nucleus synthesis ribosome.
Conclusion
Today You know about Nucleus in depth chapter of class 9 Biology The fundamental unit of life. Hope You like our article if you have any query related to Nucleus or science please write in the comment section below. I will reply as soon as possible