discribe the structure of nucleus.
Answers
Answer:
here is answer mate
Explanation:
Nucleus is seen as a dense spherical oval, structure usually located in the centre of the cell .Robert Brown discovered the nucleus in 1831 . The components present in nucleus are
nuclear membrane
nucleo plasm
nucleolus
chromatin material
genes
Nuclear membrane : It is the doubled layer covering around the nucleus . There is a space between outer and nuclear membrane . The membrane has several pores called nuclear pores . Movement of materials between nucleus and cytoplasm through these pores.
Nucleo plasm : It is a homogeneous semi fluid (protoplasm) within the cell membrane in which chromatin and nuclei are held
Nucleolus : It is a spherical granular body found in nucleus . It is not surrounded by any membrane . It is made up of RNA (Ribo Nucleic Acid ) and a few proteins . The main function of nucleus is to synthesis proteins and manufacture ribosomes .
Chromatin materials : These are very fine thread like structure distributed in nucleoplasm . At the time of cell division the chromatin becomes thick and ribbon which are known as chromosomes they are made up of DNA (Deoxy Ribo Nucleic Acid) molecules. Structurally every chromosomes are made up of two chromatin that is held at a point called centromeres
Genes :A gene is chemically a segment of DNA which helps to transmit heriditary characters from parents to off springs . Genes are arranged in a single linear order along the chromosomes . Every species has a fixed number of chromosomes . In human beings every cell consists of 46 pairs of chromosomes