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Introduction to Cells. Unit 3. In your own words tell me what you already know about cells (5 complete sentences). Quizlet. 1. Cell- basic unit of life 2. Cell membrane- thin flexible barrier that separates the cell from its environment
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Introduction to Cells Unit 3
In your own words tell me what you already know about cells (5 complete sentences).
Quizlet 1. Cell- basic unit of life 2. Cell membrane- thin flexible barrier that separates the cell from its environment 3. Cell theory- theory that all living things are made of cells, cells are the basic units of structure and function, and new cells come from previously existing cells 4. eukaryote- cell with DNA that is enclosed in a nucleus 5. nucleus- cell structure that contains genetic material 6. prokaryote- cell with DNA not enclosed in a nucleus
What is a cell? • Cells are the basic unit of all life. • Cells are full of working parts called organelles, that perform their own jobs. • Cells are the smallest unit in any organism.
Cell Theory • The Cell Theory is an important concept in Biology. It states: • All living things are made up of cells • Cells are the basic units of structure and function in living things. • New cells come from existing cells.
Living organisms can be made up of one cell or millions of cells. • Unicellular- organisms that consist of only one cell. • Multicellular- organisms that consist of many cells
Examples of Unicellular Organisms Bacteria: E. Coli are a mostly friendly bacteria that live in the intestines of humans. Amoeba: A Pond water predator that eats other unicellular organisms.
Examples of Multicellular Organisms Animals: Mammals, Fish, Reptiles Plants: Flowers, Grasses, Trees
Cell Types • There are two broad cell type categories: 1. Prokaryotic- cells that do not enclose DNA in a nucleus. 2. Eukaryotic- cells that enclose DNA in a nucleus.
Prokaryotic Cells • First cell type on earth • No membrane bound nucleus • Prokaryotic Cells are smaller and simpler than eukaryotic cells. • Nucleoid = region of DNA concentration • Organelles not bound by membranes • Example of Prokaryotic Cell: Bacteria
Eukaryotic Cells • Eukaryotic Cells are larger and more complex than Prokaryotic Cells. • Nucleus bound by membrane • Possess many organelles. • Types of Eukaryotic Cells: Animal and Plant Cells