The nucleus is often called the “brains or control center” of the cell. This is the organelle in a cell that helps the cell in making proteins and houses the all-important DNA for reproduction.

The nucleus has the ability to send out instructions to various other cell parts so that they perform their functions.  Both plant cells and animal cells have nuclei, however, bacteria cells don’t have a nucleus.

Bacteria cells aren’t sophisticated enough so their DNA simply float around within the cell itself.

The nucleus is pretty important and it has its own membrane that surrounds it.

Most cells only have one nucleus, mainly because you really only need one “brain” and it could get confusing with conflicting instructions. However, there are some rare exceptions where some cells do have two nuclei.

The nucleus is a bit complex and it has many parts:

  • Nuclear envelope: this consists of two different membranes, and inner and an outer membrane. The envelope acts as a protection for the nucleus, keeping it safe from all of the other cytoplasm within the cell as well as keeping the special nucleus molecules from escaping.
  • Nucleolus: This is a larger structure inside the nucleus that is responsible for making RNA and ribosomes.
  • Nucleoplasm: This is a liquid that is inside the nucleus.
  • Chromatin: This is made up of DNA and proteins and they are important as they organize themselves into chromosomes before the cell divides.
  • Pores: These are tiny channels that are in the nuclear envelope, and they let smaller molecules pass through such as messenger RNA molecules. However, they are too small for the larger DNA molecules to escape from inside the nucleus.
  • Ribosome: These are created inside the nucleus and then sent outside of the nucleus for the job of protein making.

The most important job

The nucleus is home to the genetic information of the cell and this is stored as DNA (deoxyribonucleic acid). The DNA contains all of the instructions for the functioning of the cell.

The DNA molecules are well organized into chromosome structures. DNA sections are called “genes” and this is where all of the hereditary information is contained.

For humans it might be eye color, hair consistency, skin color, etc.

The Nucleus has other duties

The nucleus is very busy and beside the DNA it also holds the RNA (ribonucleic acid). This is important for making proteins and is called “translation” or “protein synthesis.”

It uses translation with RNA for the configuration of amino acids, changing them into special proteins needed by the cell. The nucleus has the ability to make exact duplicates of the DNA that it holds.

The nucleus needs to get information out to the rest of the cell and it does this with a process called “transcription.”

It also uses transcription to make copies of the DNA instructions. Without a nucleus, the cell couldn’t function.

Fun Facts about the Nucleus

  • Who’s First? – The very first cell organelle that scientists discovered was the nucleus
  • A little/big Organelle – The nucleus is only one of the cell’s organelles, but it takes up about 10% of the volume of the cell.
  • Like packing a parachute – DNA is incredibly organized with proteins and is packed very tightly in the nucleus. If you unwound the DNA it would be around six feet long.
  • Not destroyed, just reformatted – When a cell divides there is a breakdown of the nuclear envelope. However, after the cell division is complete, the nuclear envelope reforms.
  • Who came up with the name? – The name “nucleus” was given by Robert Brown, a Scottish Botanist.
  • Cells get old – Scientific study is showing that the nucleolus may play a role in the aging of a cell.

Interesting Facts about Biology

  • Both avocadoes and tomatoes are considered to be fruits.
  • You might think that fungi (such as mushrooms) or algae (such as seaweed) are plants, but they aren’t. They are in their own unique kingdom.
  • Many of the medications that we currently use are actually made from the chemicals that plants create when they are trying to protect themselves.
  • So far, scientists have discovered over 12,000 species of mosses.
  • Over time, certain plants have become the “home” for animals that prey on the other animals that try to come and eat the plant.
  • The average human blinks their eyes fifteen times each minute.

Nucleus Quiz

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