CHARACTERISTICS OF LIFE

Is Sammy Alive?

1.Living things are MADE OF UNITS CALLED CELLS Unicellular – single cell Unicellular – single cell (bacteria, yeast) Multicellular – many cells (plants, animals) Multicellular – many cells (plants, animals)

2.Living things REPRODUCE SEXUAL – two cells from different parents unite to produce the first cell of a new organism SEXUAL – two cells from different parents unite to produce the first cell of a new organism ( humans, plants, mammals) ASEXUAL – single parent reproduces by itself (hydra, bacteria, yeast) ASEXUAL – single parent reproduces by itself (hydra, bacteria, yeast)

3. Living things are BASED ON A GENETIC CODE Inherit traits from parents Inherit traits from parents Carried by DNA Carried by DNA

4. Living things GROW AND DEVELOP Lifespan Lifespan Birth to death Birth to death

5. Living things obtain and use ENERGY (food, diet) ANABOLISM – chemical reaction “building” small parts into large parts (PHOTOSYNTHESIS) CATABOLISM – chemical reaction “breaking down” CATABOLISM – chemical reaction “breaking down” large parts into small parts (DIGESTION)

ENERGY continued… METABOLISM – combination of building and breaking down food METABOLISM – combination of building and breaking down food

6. Living things respond to their ENVIRONMENT Adaptations thru natural selection Adaptations thru natural selection IRRITABILITY – ability to react to a stimulus IRRITABILITY – ability to react to a stimulus (light, temperature, moisture) (light, temperature, moisture)

7. Living things maintain an internal BALANCE HOMEOSTASIS – stable condition (migration, fever, shivering)

8. Living things EVOLVE Organisms change over time in order to adapt to their environment Organisms change over time in order to adapt to their environment

Which Characteristic? Living things…… 1. Are made of cells 2. Reproduce 3. Genetic Code 4. Grow and Develop 5. Obtain and Use Energy 6. Respond to their Environment 7. Maintain an Internal Balance (homeostasis) 8. Evolve

Polar Bear Ursus maritimus Cell structure: Multicellular: fur, claws, sharp teeth Cell structure: Multicellular: fur, claws, sharp teeth Reproduction: slowest reproduction of all mammals; 2 cubs/litter; 5 litters in a lifetime Reproduction: slowest reproduction of all mammals; 2 cubs/litter; 5 litters in a lifetime Diet: seals, and sometimes ravens, arctic foxes Diet: seals, and sometimes ravens, arctic foxes Lifespan: years. Growth: meters tall (8-10ft.); kg (550-1,700 lbs.) Lifespan: years. Growth: meters tall (8-10ft.); kg (550-1,700 lbs.) Adaptations to cold: 2 layers of fur, layer of blubber, black skin Adaptations to cold: 2 layers of fur, layer of blubber, black skin