Name _________________________ Class ______ Date _________
TEKS 6.12B
Recognize that the presence of a nucleus determines whether a cell is prokaryotic or eukaryotic.
Grade 6
Lesson 6.12B
All living things are made up of cells. Some living things consist of only one cell. Others are made up of millions of cells that work together. Different organisms contain different kinds of cells, but all cells have two features in common.
• All cells are surrounded by a barrier called a cell membrane.
• All cells contain genetic material called DNA at some point in their lives. This genetic material carries instructions that cells need to carry out all the functions of life.
Cells fall into two broad categories, depending on whether they have a nucleus. A nucleus ( NOO klee us; plural nuclei ) is a dense area in a cell that contains the genetic material. The nucleus controls many of the cell’s activities. Cells that have a nucleus are called eukaryotic cells (yoo kar ee AH tic).
Cells that do not have a nucleus are called prokaryotic cells (pro kary ee AH tic) .
Eukaryotic Cells In eukaryotic cells, the genetic material is contained in a nucleus.
The nucleus is covered by its own membrane. Eukaryotic cells are usually larger and more complex than prokaryotic cells. They usually include many other structures and membranes. Many eukaryotic cells are specialized, which means they perform a specific function. Some eukaryotic organisms are single-celled. Others, such as plants, animals, and fungi, are many-celled. The picture below shows two different eukaryotic cells.
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Name _________________________ Class ______ Date _________
Prokaryotic Cells In prokaryotic cells, the genetic material is not contained in a nucleus. These cells are usually, but not always, smaller and simpler than eukaryotic cells. Prokaryotic cells are found only as single-celled organisms. These organisms can carry out all the functions of life. They grow, reproduce, and respond to the environment. Some can move. Prokaryotic organisms include those known as bacteria.
Grade 6
Lesson 6.12B
1.
Identify In what kind of cell would you find a nucleus?
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1. Define What is a cell nucleus?
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Name _________________________ Class ______ Date _________
Grade 6
Lesson 6.12B
2. Recognize What determines whether a cell is prokaryotic or eukaryotic?
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3. Compare and Contrast What are two differences, in addition to your answer to
Question 2, between prokaryotic and eukaryotic cells?
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