Introduction to CellsUnit 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:

1. All living things are made up of cells

2. Cells are the basic units of structure and function in living things.

3. 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

Prokaryotic Cell

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

Eukaryotic Cells

Prokaryotes vs Eukaryotes