1 Facts About Living Things

2 What Are the Main Characteristics of organisms? 1.Made of CELLS 2.REPRODUCE 3.Have a UNIVERSAL GENETIC CODE 4.GROW and DEVELOP 5.Require ENERGY (food) and EXCHANGE materials with surroundings (water, wastes, gases) 6.Respond to their ENVIRONMENT 7.Maintain a STABLE ENVIRONMENT -Homeostasis 8. Living things CHANGE OVER TIME.

3 Living things are organized…

4 LEVELS OF ORGANIZATION Nonliving Levels: 1.ATOM (element) 2.MOLECULE (compounds like carbohydrates & proteins) 3.ORGANELLES (nucleus, ER, Golgi …)

5 LEVELS OF ORGANIZATION Living Levels: 1.CELL (makes up ALL organisms) 2.TISSUE (cells working together 3.ORGAN (heart, brain, stomach …) 4.ORGAN SYSTEMS (respiratory, circulatory …) 5.ORGANISM

6 Number of Cells Although ALL living things are made of cells, organisms may be: Unicellular – composed of one cell Multicellular- composed of many cells that may organize into tissues, etc.

7 Multicellular Organisms Cells in multicellular organisms often specialize (take on different shapes & functions)

8 Cell Specialization Cells in a multi- cellular organism become specialized by turning different genes on and off This is known as DIFFERENTIATION

9 Specialized Animal Cells Muscle cellsRed blood cells Cheek cells

10 Specialized Plant cells Xylem cells Pollen Guard Cells

11 Organization Levels of Life Atoms to Organisms

12 ATOMS  MOLECULES  ORGANELLES Nonliving Levels

13 CELLS – life starts here TISSUES – Similar cells working together Living Levels  

14 ORGANS ORGAN SYSTEMS ORGANISM Different tissues working together Different organs working together  More Living Levels

15 To do… 1.Please read pages , and answer questions # 1, 4, 5 and 6 on page 22 2.Please read pages While reading, complete the accompanying worksheet.