Transcript Chapter 1
Chapter 1: A View of Life Characteristics of Life Living Things are organized Small molecules form larger molecule within a cell Some organisms are unicellular Plants and animals are multicellular In multi cellular organisms Cells combine to form tissues Tissues combine to form organs Organs combine to form organ systems Organ systems make the organism Living Things Acquire Materials and Energy Energy is the ability to do the work it takes to maintain life Metabolism is all the chemical reactions that occur in a cell Living Things Acquire Materials and Energy Continued Ultimate source of energy is the sun Plants, bacteria, and algae can convert light energy into chemical energy through photosynthesis For metabolic processes to continue, there must be a stable tempeature, moisture level, pH, and other factors This is called homeostasis Living Things Respond Organisms respond to their environment This is called behavior Living Things Reproduce and Develop All organisms can reproduce, or make more organisms like itself Can be asexual or sexual Living Things Have Adaptations Adaptations are modifications that makes an organisms suited for its way of life Evolution: A Core Concept in Biology Diversity of Life Categories of classification From most specific to least specific Species, Genus, Family, Order, Class, Phylum, Kingdom, Domain Scientific Naming Species are described using the genus and species The genus is capitalized and the species is lower-case, the whole name is italicized Homo sapiens Occasionally, the genus will be abbreviated with the first letter and a period if the genus is considered obvious T. rex Domains Bacteria, Archaea, Eukarya Bacteria and Archaea are prokaryotes Kingdoms In Eukarya there are four Kingdoms Animalia, Protista, Fungi, Plantae Science: A Way of Knowing Observation First step of the scientific method Collected with the senses Hypothesis Arrived at through inductive reasoning by looking at a phenomena at explaining it using all the information avaiable Must be testable Experiment/Further Observation What is an experiment Designed test of a hypothesis Experimental design is important to make sure only one variable is being tested This can be accomplished by having an experimental group and a control group. Experiment/Further Observation Continued Models can be used to represent complex systems in a way that is easy to comprehend Global climate is often model to bring it to a reasonable level Data Data are the result of an experiment Can be qualitative or quantitative Quantitative is usually preferred because it can be compared Conclusion Derived from the data States whether a hypothesis is supported or not Experiments can never prove anything, but can only disprove the null hypothesis Scientific Theory Accepted explanations for observed phenomena Based on several experiments “Best explanation so far” If theory becomes accepted for a very long period of time it can become a principle or law Science and Bioethical Issues Biodiversity Maintaining biodiversity is important for ecosystems Extinction Species going extinct is a concern