CHARACTERISTICS OF LIFE Unit 2 Biodiversity Its Alive

CHARACTERISTICS OF LIFE Unit 2 - Biodiversity

It’s Alive! 1. Are made up of units called cells 2. Obtain and use materials and energy (Metabolism) 3. Grow and develop 4. Reproduce 5. Are based on a universal genetic code 6. Respond to their environment 7. Change over time. 8. Maintain a constant environment.

1. Are made up of units called cells Unicellular Organisms � Living Organism Made Up Of One Cell Multicellular Organisms � Living Organism Made Up Of Many, Specialized Cells

2. Obtain and use materials and energy Metabolism: the way in which an organism breaks down and uses it’s energy. Autotrophs can make their own food (some use the sun, some use chemicals). Heterotrophs can NOT make their own food. They must consume other organisms � Herbivores eat plants � Carnivores eat meat � Omnivores eat plants & animals � Detritivores eat dead decaying matter � Decomposer break down dead decaying matter

3. Grow and develop Organisms grow by producing MORE CELLS (mitosis) & by cell ENLARGEMENT Organisms develop as they mature into an adult organism

4. Reproduce � � � Sexual Reproduction Involves 2 parents Egg fertilized by sperm to make a ZYGOTE Offspring DIFFERENT from parents Asexual Reproduction Involves a single organism or cell Cell divides Offspring IDENTICAL to parent

5. Are based on a universal genetic code DNA (deoxyribonucleic acid) carries the genetic code for all organisms All organisms contain DNA codes for the proteins that make up cells & do all the work

6. Respond to their environment Organisms Respond to stimuli (Temperature, Water, Food Supplies, etc. ) In Order To Survive & Reproduce

7. Change over time Groups Of Organisms (Not Individuals) Change Over Time (evolution) In Order To Survive Within Changing Environments. Fossil records show changes in groups of organisms

8. Maintain a constant environment. Keeping The Internal Environment (Homeostasis) Of The Cell or Organism Within The Ranges Required For Life Stable internal conditions of p. H, temperature, water balance, etc.

Life is organized on several levels: Atoms Molecules Organelles Cells life starts here Tissues Organs System Organism Kingdoms start here Population Community Ecosystem Biosphere