The diversity of cellular life

1. The diversity of cellular life

2. Cell are the basis of life • Even though life is extremely diverse, it is important to remember that all life is made up of cells • Organisms can be unicellular or multicellular

3. Unicellular Organism • A single cell can be an organism • Unicellular organisms do everything a living thing is required to do • They grow and develop, respond to the environment, reproduce, etc • In terms of numbers, unicellular organisms dominate life on earth

4. Multicellular Organisms • These are organisms made of many cells • All multicellular organisms depend on communication and cooperation among specialized cells

5. Cell specialization • Is the process by which cells throughout an organism develop in different ways to perform different tasks • Examples: Blood cells, bone cells, skin cells, nerve cells, etc.

6. Levels of organization • Multicellular organisms have different levels of organization that make it easier to describe cells • The levels are • 1. cells • 2. tissues • 3. organ • 4. organ systems

7. Tissues • These are similar types of cells grouped into units • Tissues are groups of cells that perform a specific function • Nervous tissue would be an example

8. Organs • Organs are groups of tissues working together to carry out a specific functions • Example: the heart

9. Organ systems An organ system is a group of organs that work together to perform specific functions

10. Why Organization? • The organization of cells, tissues, organs, and organ systems in a body creates a division of labor among cells that make multicellular life possible • All cells have an interdependence upon others cells and the survival of each cell and the entire organism depends on the specific functioning of all cells