Function of Nucleus

Nucleus

It is a large, spherical organelle present in the cell. It is considered to be the brain of the cell. Nucleus is surrounded by a membrane called the nuclear membrane and is filled with a semi-solid substance called the nucleoplasm. It is the most important component of the living cell. After staining, it can be easily seen with the help of a microscope. In Animal cells, nucleus lies at the centre of the cell whereas in Plant cells, it is present at the periphery of the cell due to presence of a large vacuole. The nucleus consists of the following four parts:

Nuclear membrane : Nucleus is separated from the cytoplasm by a membrane called nuclear membrane. This membrane is also porous and allows the movement of certain selected materials between the cytoplasm and the nucleus.

Nucleoplasm: The dense fluid present in the nucleus is called nucleoplasm.

Chromatin: Some fine, thread like structures, composed of deoxy-ribonucleic acid (DNA) are suspended in the nucleoplasm. These are called chromatin fibres. In the dividing nucleus, these chromatin fibres condense and form chromosomes. Due to this, chromosomes are only visible in dividing cells. These chromosomes carry genes. Genes are responsible for passing genetic characteristics from the parents offspring. Genes contains genetic codes which are responsible for the unique physical character of an animal or a plant. A child receives one copy of each gene from the mother and another copy of same gene from the father.

Nucleolus : It is a small spherical body present inside the nucleus. It is rich in RNA (Ribonucleic Acid). It is a naked irregular structure which is attached to the chromatin.

Functions of Nucleus :-

The nucleus controls all the metabolic activities of the cell.

Nucleus acts as control centre of the activities of the cell

It is responsible for passing genetic characteristics from the parents to the offspring. If a person has brown eyes, his son/daughter may also have brown eyes. If a woman has curly hair, her son/daughter may also have curly hair. However, different combinations of genes from parents may result in different characteristics.

Nucleus is the storehouse of genes. Without nucleus, cell can neither survive nor shows specialized activities. Heredity is the transfer of character from parents to offspring.

Sample Questions

(More Questions for each concept available in Login)

Question : 1

Phosphorus is a structural element in ____________________ .
A. Proteins	B. Cytochrome	C. Carbohydrates	D. DNA
Right Option : D
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Question : 2

The growth of cells is regulated by _____________________>
A. Mitochondrion	B. Vacuole	C. Nucleus	D. Golgi complex
Right Option : C
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Question : 3

Which cell organelle is known as the control centre of the cell?
A. Nucleus
B. Chloroplast
C. mitochondria
D. Endoplasmic retichlum
Right Option : A
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