How do we know if something is living or non-living? Living Things How do we know if something is living or non-living?

What are 5 characteristics that every living thing has in common? Please answer this in your notebooks

Biology Biology: Study of Life Scientists that study life are called Biologists Biologists study 3 important questions: 1) How do living things work? 2) How do living things interact with the environment? 3) How do living things change over time?

Characteristics of Life There are 7 characteristics of life: Organization and Cells Response to a Stimulus Homeostasis Metabolism Growth and Development Reproduction Change Through Time

1. Organization and Cells Organization: High degree of order within an organisms internal and external parts ……Ex) Humans Cells: smallest unit that can perform all of life’s processes What is the difference between an Unicellular and a Multicellular organism and give me an example of each?

Hierarchy of Organization Within an organism, there is a Hierarchy of Organization. Organism Organ System Organ: Carry out specialized jobs Tissue: Group of Cells Cell Organelle Biological Model 6

2. Response to a Stimulus What is a stimulus? Physical or chemical change in the internal or external environment Why do organisms need to respond to a Stimulus? TO STAY ALIVE!

3. Homeostasis Maintenance of a stable level of internal conditions even though environmental conditions are constantly changing Temp., water content, salinity, acidity, etc

4. Metabolism Energy powers all of life’s processes Metabolism is defined as the sum of all the chemical reactions that take in and transfer energy Plants? Humans?

5. Growth and Development All living things grow and increase in size Development is the process by which an organism becomes a mature adult Cell division is one form of growth and increase. Forming two cells from one existing

6. Reproduction All organisms produce new organisms in a process called reproduction Genes: Short segment of DNA that are passed to offspring Two ways: Sexual and Asexual

7. Change through Time Populations of living organisms evolve or change through time to compete or survive