Question

Q.2 Explain the structure and function
of nuclues

please solve this question class 8 science. please write in short​

Answer 1

Answer:

nucleus

The nucleus is a spherical-shaped organelle that is present in every eukaryotic cell. The Nucleus is the control centre of eukaryotic cells. It is also responsible for the coordination of genes and gene expression. The structure of the nucleus includes nuclear membrane, chromosomes, nucleoplasm, and nucleolus.

Explanation:

functions of nucleus

Nucleus is a membrane bound structure that contains the cell’s hereditary information and controls the cell’s growth and reproduction.

• Nucleus is present in all eukaryotic cells, they may be absent in few cells like the mammalian RBCs.
• The shape of the nucleus is mostly round, it may be oval, disc shaped depending on the type of cell.
• It is the command center of a eukaryotic cell and is commonly the most prominent organelle in a cell.
• The nuclear envelope is a double membrane that separates the nucleus from the cytoplasm.
• All traffic into and out of the nucleus passes through nuclear pores that bridge the double membranes.
• Inbound traffic includes all nuclear proteins and ribosomal proteins destined for the nucleolus.
• Outbound traffic includes mRNAs and ribosomal subunits.
• The nuclear envelope consists of phospholipids that form a lipid bilayer.
• The nuclear envelope is perforated with numerous pores called nuclear pores.
• The envelope helps to maintain the shape of the nucleus and assists in regulating the flow of molecules into and out of the nucleus through nuclear pores.
• The nuclear envelope is connected with the endoplasmic reticulum (ER) in such a way that the internal compartment of the nuclear envelope is continuous with the lumen of the ER.

structure of nucleus

Chromosomes consist of DNA, which contains heredity information and instructions for cell growth, development, and reproduction.

When a cell is “resting” i.e. not dividing, the chromosomes are organized into long entangled structures called chromatin and not into individual chromosomes.

Nucleoplasm is the gelatinous substance within the nuclear envelope.

The nucleolus is not surrounded by a membrane, it is a densely stained structure found in the nucleus.