8 22 2012 Chapter 1 Characteristics of Life All living things are composed of one or more cells Single celled Multi celled Prokaryotes Eukaryotes Viruses intracellular parasites Regulate their metabolic processes and convert molecules obtained from the environment into new molecules Homeostasis regulation of an organisms internal environment Metabolism chemical reactions that convert energy into a usable form and is essential for nutrition growth and the repairing of cells Homeostatic mechanism body temperature regulation Organisms grow and develop Increase number of cells Increase size of cells Indeterminate growth some organisms that continue to grow in size throughout their life Example Fish Organisms respond to stimuli Movement may not be obvious external but still occurs Responsiveness respond to stimuli changes in internal or external environment Phototaxis responsiveness to light negative away from positive towards Example Red Snapper negative phototaxis Organisms use genetic information to reproduce Reproduction Asexual clone divide to produce two identical organisms Sexual sperm egg fertilized egg unique set of characteristics characteristics of both parents Adaptation Organisms adapt to a changing environment Adapt to increase survivorship in a particular environment Evolution Charles Darwin The Origin of Species 1859 Natural Selection Raw material for natural selection is mutations that can be good bad or silent The Organization of Life 8 22 2012 Chemical Level Atoms Molecules Organelle s Cells Tissues nervous muscle Organs Organ Ecological Organization Population same species in a particular area Systems Organism Example Bluefin Tuna Habitat the environment where the organism or population is found Community all the populations in a particular area Ecology interrelationships between communities and their relations with the environment Ecosystem Community plus non living environment Energy Flow through Systems Producers autotrophs Produce food from simple raw materials Algae plants bacteria Photosynthesis CO2 H2O Sunlight Food Oxygen Consumers heterotrophs Dependent upon produces Animals Respiration Food Oxygen CO2 H2O Energy Decomposers Bacteria fungi Recycle nutrients Variety of Organisms Species basic unit of classification Similar both structurally and functionally Must be able to reproduce and create viable offspring non sterile Domain Kingdom Phylum Class Order Order Family Genus Species Domains 3 Lepomis genus annularis species Bacteria Eukarya Archaea Kingdoms 6 Bacteria prokaryotes Simple no membrane bound organelles Archaea prokaryotes Methanogens methane producing organisms 8 22 2012 Protozoa algae molds slime molds Protisita eukaryotes Fungi eukaryotes Important decomposers Plantae eukaryotes Photosynthetic organisms Rigid cell wall chlorophyll Animalia eukaryotes Scientific Method Framework that most scientists use 1 Ask questions make observations formulate a hypothesis 2 Make predictions based on hypothesis 3 Perform experiments and make observations 4 Prediction supported or not 5 Hypothesis is supported by many experiments or observations theory principle or law