Chapter 4 – The Organization of Life

The Kingdoms There are six (6): The first two are both single-celled, lack defined nuclei, and reproduce by cell division Archaebacteria- found in harsh environments Thermophiles are found in very hot places like hot springs in Yellowstone Methanogenes are found in swampy methane producing places

The Kingdoms (cont.) 2. Eubacteria – very common E.coli- found within the human digestive system Blue-green algae (cynobacteria)- found in many types fresh water Bacteria play a huge role in breaking down dead organisms and recycling nutrients in the environment

The Kingdoms (cont.) 3. Fungi – have cell walls, are found on land, and absorb their food. Along with bacteria fungi play a huge role in breaking down dead organisms and recycling nutrients to the environment.

The Kingdoms (cont.) 4. Protists - most are single-celled, but some are not- most are found in water Some protists are more animal like and are heterotrophic- paramecium/amoeba -many cause diseases Phytoplankton - can do photosynthesis and include single celled and multicellular organisms like diatoms and kelp – are more plant like

The Kingdoms (cont.) 5. Plants- contain a cell wall, are multicellular, one of only two kingdoms to do photosynthesis to produce its own food. (What is the other?)

The Kingdoms (cont.) 6. Animal - multicellular , has no cell wall, are found in water and on land, are heterotrophic (ingest their food)

Plants Lower order plants are the mosses and ferns Mosses/Lichens

Plants Higher order plants include gymnosperms (conifers) and angiosperms (flowering plants). Gymnosperm/Conifer have specialized needle-like leaves and bear their seeds in cones. Angiosperms/Flowering plants come in many forms and includes most of the plants humans and animals use as food .

Animals Two major groups: Invertebrates- have no spine (backbone) includes many classes of animal Insects are the most numerous and successful of all types of animals because they are small, mobile, have a waterproof exoskeleton and reproduce quickly

Animals Invertebrates- also includes sponges, coral, molluscs, and worms.

Animals Vertebrates- animals that do have a spine (backbone) include both ectothermic (cold-blooded) and endothermic (warm-blooded) organisms These ectothermic animals have a body temperature that is the same as their environment.

Organization in an Ecosystem An ecosystem is composed of both biotic factors (living) and abiotic factors (nonliving) and all are connected. Organized like this: Organism species population community ecosystem

Organism Any living thing.

Species A group of organisms that are so closely related that they can mate and produce fertile offspring.

Population All the members of the same species living in the same place at the same time. remember that a population is defined only by its boundaries. For example: A population of grasshoppers in a cornfield.

Community All of the different populations living at the same place at the same time.

Ecosystem Includes all the members of the community and all abiotic factors. Sunlight Precipitation Soil

Habitat An organisms’ habitat is the type of ecosystem (or biome) it lives in. It gets all the resources it needs here. For example: Taiga- Coral Reef- Tropical rainforest Organisms are so well-suited for habitats through a process of natural selection leading to evolution. This process occurs when an organism has some adaptation (advantageous trait) that allows it to better survive and reproduce passing on that trait. As this trait is passed on more and more (through reproduction) it will eventually show in most members of the population. This change in the characteristics of a population is Evolution.

The Theory of Evolution by Natural Selection Has 5 major points: 1. All organisms have a greater reproductive potential than is ever realized. More offspring are produced than could possibly survive. 2. The environment is hostile and contains limited resources. 3. Inherited variations exist. Some are advantageous, some harmful. Variations are passed to offspring. 4. Those with advantageous traits are more likely to survive. 5. Advantageous trait will be passed on in greater frequency to subsequent generations.

Evolutionary Processes Convergent evolution – independent evolution of similar structures (analogous) for similar purposes. For example: Bird wings & insect wings show similarities in structure

Evolutionary Processes (cont.) Co-evolution - process in which two species evolve in response to one another. For example: Milkweed/Tussock Caterpillar and Crab/Sea snail

Evolutionary Processes (cont.) Artificial Selection - selective breeding by humans for desired traits. For example: Different Dog Breeds

Evolution of Resistance An organism has a natural resistance to some chemical or pathogen that allows it to survive. It then passes on the gene for that trait until it shows in the entire population. For example: Drug resistant strains of Tuberculosis Insects become resistant to pesticides

The End