The Different Jobs of Cells

1. The Different Jobs of Cells Chapter 2 Section 2

2. Choosing the Right Tool • What tool would you use to saw a piece of wood? • The cells in us (a multi-celled organism) are specialized. • Different kinds of specialized cells work as a team to perform the life activities of a many-celled organism.

3. Human Cells • Human cells come in a variety of shapes. • The shape and size of a cell can be related to its function.

4. Types of Human Cells • Fat cells- stores so much fat that nucleus gets pushed against cell membrane. • Skin cells- mostly flat and close together; form a protective layer for your body • Bone cells- surrounded by hard substance made of calcium and phosphorus • Nerve cells- long; have many branches; allows cells to send and receive messages quickly • Muscle cells- long; have many fibers that can contract and relax

5. Plant Cells • Plants have different types of cells in their leaves, roots, and stems. • Each type of cells has a different job.

6. Types of Plant Cells • Stem cells- long and tube-shaped; move water through plant • Root cells- block shaped; do not contain chloroplast • Leaf cells- brick shaped; contain many chloroplasts

7. Cell Organization • Cells are organized into systems that perform functions that keep the organism healthy and alive. • Tissues: Groups of similar cells that all do the same sort of work • Example: muscle tissue is made up of muscle cells. Bone tissue is made up of bone cells. • Organs: different types of tissues working together • Example: stomach is an organ with muscle and nerve tissue • Organ systems: group of organs working together to do a certain job • Example: stomach, mouth, liver, intestines are involved in digestion