Characteristics of Life

1. Characteristics of Life

2. 1. All organisms are made of cells Cells are the smallest unit of life

3. 2. All organisms need energy Any living organism needs energy to live They take in and use energy.

4. 3. All organisms respond to the environment What happens to an organism depends on the environment they are living in.

5. 4. All organisms reproduce Living organisms can make more of themselves Two types: asexual sexual.

6. 5. All organisms grow and develop Get bigger as they get older.

7. 6. All organisms carry DNA Carry their own genetic code Traits are passed to offspring

8. 7. Internal Balance (Homeostasis) Living things maintain stable internal conditions Examples Temperature Water Balance Heart Beat

9. Is It Alive?

10. ECOLOGY • Key Knowledge: • Matter cycles, energy flows • Abiotic factors cause changes in biotic factors in a ecosystem

11. Ecosystem Structure

12. Abiotic: Non-living parts of the environment • Soil • Sunlight • Climate • Temperature • Rainfall • Nutrients

13. Biotic: living parts of the environment • Plant • Animals • Decomposers (Bacteria and Fungus)

14. General Organization • Organism= any individual living thing • Population= Individual organisms of a single species in one area. • Community=more than onepopulationliving in the same area.

16. Different species of fish Different species of corals (animals) Starfish (animal) Example of a Community Algae (microscopic plants)

17. General Organization • Ecosystem= All the populations and abiotic factors in an area. • Habitat=the environment that a particular species prefers within an ecosystem • Niche=the role that an organism fills “job” • Biomes=Ecosystems with similar characteristics.

19. Characteristics of a Biome • No distinct boundaries • Defined by types of plants • Similar climate conditions, but may be located in a totally different part of the world (Africa and Asia) • Classification of biomes: • land biomes • water biomes (marine or freshwater)

21. Autotroph Feeding Self Can make their own food through energy from the sun or inorganic substances AKA: Primary Producer

22. Heterotroph Other Feeding Obtains energy by eating other organisms, AKA: Consumers

23. Types of Consumers Primary consumers: eat producers (herbivores) Secondary consumers: eats both producers & consumers (omnivores) Tertiary consumers: top predator (carnivore)

24. Trophic levels are a way of identifying what kinds of food an organism uses. 1st trophic level= primary producers 2ndtrophic level= primary consumers 3rd trophic level= secondary consumers 4th trophic level= tertiary consumer

25. Decomposers & Scavengers • Decomposers feed on wastes & dead material from all trophic levels • Ex: bacteria, fungi • Scavengers are consumers that eat dead animals (like road kill) • Ex: vulture

26. Energy in an ecosystem is transferred (cycles) through the trophic levels of that ecosystem

27. Biomass and Energy Transfer 1 hawk 10 snakes 100 mice feed 1000 plants feed Rule of 10****- Only 10% of the energy is transferred to the next organism. Biomass- amount of living matter, number of organisms, or determines the amount of energy

29. Very few animals feed on only one food source, food webs are a more accurate picture of how animals feed.

30. Methyl Mercury DDT Biological Magnification • The build-up of toxins in living organisms with movement up the trophic levels . • Toxins collect in at the top of food web because top consumers eat so much. • Examples:

31. DDT:Dichlorodiphenyltrichloroethane • Developed during WWII as a pesticide • Very high levels of DDT were found in top consumers. • DDT is stored in fat. • Organisms died or had reproductive problems • Banned in US and Canada during the 70’s. • Still found in almost all living things • Developing countries are still use DDT

33. DDT ( soil ) Almost 40 years later! PCB's ( industrial waste) Polychlorinated Biphenyl Methyl Mercury ( Fish) Current Chemicals of Concern Dioxin (plastic)

34. Community Interactions

35. Community Interactions In order to sustain an environment, organisms and abiotic factors interact EXAMPLES: • Symbiosis • Succession

36. Forms of Species Interaction Symbiosis: relationships between two species (3 types) 1. Parasitism: one organism benefits at another’s expense (humans and tape worm) 2. Commensalism: one organism benefits while the other is unaffected(anemone and clown fish) 3. Mutualism: both organisms benefit from the interaction (rhino and bird)

37. Forms of Species Interaction Continued Competition: two species are fighting for the same resources Predation:one species hunts the other Ecological succession:change in the types of species in a community observed over time

38. Invasive Species • A species that is brought by HUMANS into a new environment and outcompetes the ones already there. • They have no competitors, no diseases so they outgrow other populations Example: Africanized honey bees, which will take over the hive of the honey bees. Example: Zebra mussels attach to boats and cover piers within months

39. Keystone Species • A species that plays a key role in the ecosystem • Increases biodiversity by keeping the number of each species in balance • Examples • Sea otter in the kelp forests • Beavers in rivers Beaver Sea Otter

40. Succession

41. Why does succession happen? Communities & environments change over time

42. 1) Primary Succession When communities form in new areas • Ex: volcanoes, rocks, etc

43. Steps of Primary Succession • Pioneer species appear lichens (grow on rock & turn it into soil) • Pioneer Species: the first organisms to occupy an area • Grass & small plants appear • Weeds & shrubs • Shallow trees (ex: pine trees) • Climax community  stable & final stage (ex: deciduous trees)

44. Climax Community A community that has achieved stability and species diversity

45. 2) Secondary Succession • Occurs in areas that were cleared by disturbance (fire, tornado, floods, etc) • faster than primary (soil already formed) • Same as primary except pioneer species are grasses instead of lichens

46. Succession leads to….. Population Growth

47. FACTORS THAT AFFECT POPULATION GROWTH • Birth Rate • Death Rate • Immigration (movement into an area) • Emigration (Movement, exiting an area)

48. TYPES OF POPULATION GROWTH

49. Exponential Growth • J-shaped curve on a graph • Population doubles every generation • Humans are reproducing this way! Humans - Trouble ahead?