Difference Between in Biology

Difference Between Nucleus And Nucleoid

The nucleus is an organelle and found in eukaryotic cells that store proteins and RNA. It is known as the largest and important cell organelle. The nucleoid is an unevenly shaped region that stores genetic material and is found in prokaryotes. Learn the difference between nucleus and nucleoid here.

Let us understand the key difference between the nucleus and nucleoid in detail.

difference between nucleus and nucleoid

Difference Between Nucleus And Nucleoid

Character Nucleus Nucleoid
Definition Nucleus is found in the eukaryotes and stores their genetic materials. Nucleoid is found in the prokaryotes and stores their genetic materials.
Size It is known as the largest and the well organized cell. It is known as the small and the well organized cell.
Chromosomes Nucleus contains several chromosomes. Nucleoid contains only one chromosome.
Shape It is spherically shaped. It is irregularly shaped.
Membrane Nucleus is surrounded by double layer membrane. Nucleoid does not contain nay membrane.
Nucleolus It is present in the nucleus. It is absent in the nucleoid.
Nucleoplasm It is present in the nucleus. It is absent in the nucleoid.
Composition It is the collection of DNA, histones, RNA, enzymes, dissolved ions, and other subnuclear bodies. It is the collection of DNA, histones, RNA, and other proteins.


The nucleus is a biological cell membrane organelle present in eukaryotic cells. It contains all the cell genomes. It is the composition of DNA, RNA, Histones except for a small fraction of mitochondrial DNA.

Nucleus helps in controlling and regulating the activities of the cell such as growth and metabolism. It carries the genes, structures that contain the genetic information.


The nucleus is the largest organelle found in mammals. It is approximately 6 micrometers and lives in about 10% of the total cell volume. The contents are placed in the nucleus sap or nucleoplasm in the rest of the cell. It is also known as Karyoplasm and is similar to the cytoplasm. Nucleoplasm is a gel-like matrix.

The dynamic behavior of the structure in the nucleus can be visible using time-lapse microscopy. The study of cells using this microscope is known as live-cell imaging. It helps in visualizing the behavior like nuclear rotation that occurs in mitosis.

Nuclear membrane

The nuclear membrane is made up of two membranes that encase the genetic materials. These membranes surround the nucleus and are present in eukaryotic cells. It consists of two cell membrane, an inner and outer membrane set out in parallel to each other. The distance between these membranes is 10 to 50 nanometer (nm).

The nuclear envelope includes phospholipids that form a lipid bilayer. It helps in maintaining the shape of the nucleus. The main function is to help in the regulation of the flow of membrane into and also out of the nucleus through nuclear pores. Such nuclear pores help in the exchange if large molecules like proteins and RNA between nucleus and cytoplasm.

Function of Nucleus

The main function of the nucleus is to control the genetic expressions and to moderate the reproduction of DNA during the cell cycle. It helps in controlling the heredity characters of an organism. It stores hereditary material like genes in the form of thin and long DNA. The other responsibilities of the organelle are protein synthesis, growth, and differentiation, cell division.

Nucleus helps in the storage of proteins and RNA in the nucleolus. It helps in the organization of messenger RNA produced for protein synthesis. The chromatins are organized into chromosomes in the nucleus. This process occurs during cell divisions.

Nucleus helps in the production of ribosomes in the nucleolus. These ribosomes are protein factories. The nucleus provides a place for genetic arrangements that are separated from the location of translation in the cytoplasm and allows levels of gene regulation that are not available to prokaryotes.


The nucleoid is the space where the genetic information, called the genophore, is found within a prokaryotic cell. Prokaryotes are divided into archaea and bacteria, which are both unicellular organisms. These organisms do not contain membrane-bound organelles.

The nucleoid also does not have a membrane around it. It is attached to the cell membrane and connects the cytoplasm. It also does not take any uniform shape and size. However, it can still be distinguished from the rest of the cell and identified under a light microscope.

The nucleoid is mostly composed of multiple compact replications of DNA in a continuous thread, in addition to RNA and proteins. The DNA in prokaryotes is double-stranded and has a circular shape. The DNA can sometimes also be found in other parts outside the nucleoid.

Eukaryotes have a nucleus that stores their genetic material, surrounded by a double membrane. It is also known as the nuclear envelope. This membrane helps in separating the contents of the nucleus from the cytoplasm. As in prokaryotes, the DNA of eukaryotes is also double-stranded.


The nucleoid is capable of controlling the activities of the cell and reproduction. It helps in the arrangements and reproduction of DNA. It consists of enzymes that help with reproduction, as well as other proteins that help in other functions and different structural roles, including the formation of DNA, regulation of the genome of the cell and cell growth.





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3 responses to “Difference Between Bryophytes And Pteridophytes”

  1. Galadima says:

    thanks for in lighting us

  2. Olatunji Akinola says:

    Thanks for lighting me more this aspect

  3. Nneka chinedu says:

    Thanks for enlightening me more on this

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