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Nucleus
Next Generation: MS.LS1.2 MS.LS1.2

Nucleus

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Description:

This lesson will describe the structure and function of the nucleus of a cell.

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Tutorial

What's Covered


Welcome to today’s lesson on the nucleus. In this lesson, you will learn descriptions of the structure and the function of the nucleus. Specifically you will learn more about:

  1. Nucleus Overview
  2. The Nuclear Envelope
  3. The Nucleolus
  4. The Chromatin

1. Nucleus Overview

The nucleus is a cellular organelle found in eukaryotic cells. Eukaryotic cells are described as cells that have a nucleus, so it makes sense that the nucleus would only be found in eukaryotic cells. The nucleus contains the cell's DNA and is basically the control center of the cell. Think of it as the brain of the cell or the control center that controls everything that's happening within the cell.

Term to Know

Nucleus

A cell organelle found in eukaryotic cells that houses the DNA and controls activity within the cell.

Example An example of a eukaryotic cell would be our cells or any other animal cells because they have a nucleus.

Term to Know

DNA

DNA stores an organism’s genetic information.

Take a look at these diagrams below to better understand the structure of the nucleus.

So the diagram above is a drawing of any eukaryotic cell. So within the cell you have the nucleus and several other different organelles.


2. Nuclear Envelope

The blue drawing to the right in the image above shows a blown-up version of the nucleus. Outside, surrounding the nucleus, we have something called a nuclear envelope. This nuclear envelope is a double layer membrane composed of two lipid bilayers.

Term to Know

Nuclear Envelope

A double membrane that surrounds the nucleus.

Within the nuclear envelope are pores; the little black dots all over represent the pores in the nuclear envelope. These pores are very important because they allow for RNA to leave the cell, along with certain ions or molecules. There are many different types of proteins embedded within this membrane as well that provide various functions.


3. Nucleolus

Another part of the structure of the nucleus is the nucleolus. The nucleolus is a structure found inside of the nucleus and the purpose of the nucleolus is to construct ribosome subunits.

Term to Know

Nucleolus

A structure found within the nucleus that produces subunits of ribosomes.

The subunits of ribosomes are made within the nucleolus. Then they'll cross through those the pores and into the cytoplasm of the cell where they will connect together and form the protein building organelles known as ribosomes.


4. Chromatin

Chromatin is contained within the nucleus, and chromatin contains our genetic information. When chromatin condenses, it will form chromosomes. Chromosomes are visible when a cell divides and the purpose of chromosomes is to allow for the passage of genetic information. When the cell is preparing to divide our DNA will condense into those chromosomes that you might be familiar with. This allows for the passing of genetic information onto the new cell. The nucleus helps to keep this genetic information organized and separate from the rest of the cell.

Term to Know

Chromatin

A form of uncondensed DNA found within the nucleus of the cell.

Term to Know

Chromosomes

A condensed form of DNA that occurs when the cell is dividing.

Summary

Today you have learned about the different structural elements of the nucleus and their functions. Specifically you learned about the functions of the cell’s nuclear envelope, nucleolus, and chromatin.

Keep up the learning and have a great day!

Source: THIS WORK IS ADAPTED FROM SOPHIA AUTHOR AMANDA SODERLIND

TERMS TO KNOW
  • Nucleus

    ​A cell organelle found in eukaryotic cells that houses the DNA and controls activity within the cell.

  • DNA

    ​DNA stores an organism’s genetic information.

  • Nuclear Envelope

    A double membrane that surrounds the nucleus.

  • Nucleolus

    A structure found within the nucleus that produces subunits of ribosomes.

  • Chromatin

    ​A form of uncondensed DNA found within the nucleus of the cell.

  • Chromosomes

    A condensed form of DNA that occurs when the cell is dividing.