Chapter One Biology Notes August 24th 2012 Living Characteristics Respiration reproduction growth Non Living Characteristics No movement don t need food Life Cells Complex Organisms We are living in the Golden Age of Biology Modern Biology is exciting and changing our culture Biology is the study of life Life is recognized by what living things do 7 Characteristics 1 They have order 2 They regulate themselves Homeostasis Maintaining steady state 3 They grow and develop 4 They respond to the environment 5 They reproduce 6 Populations evolve 7 They use energy Theme One The scope of life and emergent property Life consists of vertical hierarchy Molecules Biosphere Be familiar with Figure 1 2 on page 5 Novel properties emerge at each step Due to the arrangements and interactions of the components Emerging properties are difficult to predict when you look at the properties at lower levels of the hierarchy Examples of Emergent Properties Photosynthesis Put all the molecules required for photosynthesis in a test tube Expose to light Photosynthesis will not occur The specific orientation of the molecules is missing Theme Two Organisms exchange matter and energy within ecosystems Every organism interacts with its environment Both are affected Example Plants use Carbon Dioxide to make food All oxygen in the atmosphere comes from photosynthesis Nutrients are recycled Energy flows from sun producers consumers Energy exists as heat Energy flowing example on page 6 Fig 1 3 Theme Three Cells are an organism s basic unit Cells are the lowest level of organization that can perform all activities of life All cells Are enclosed by a membrane Use DNA as the recipe for the process of life 2 Types of cells Prokaryotic no nucleus and Eukaryotic true nucleus Theme Four The continuity of life is based on info in the DNA Chromosomes contain most of a cell s genetic material in the form of DNA DNA is the substance of genes Genes are the units of inheritance that transmit information from parents to offspring Theme Five Diversity is the hallmark of life and the diverse forms of life fit their functions There are 3 main groups of life called domains 1 Eukarya 2 Bacteria 3 Archae August 27 2012 Eukaryote True nucleus Review Living Organisms Can Be Classified Protista include organisms such as algae kelp slime molds and protozoans The structure and function of diverse components of life are related Theme Six Evolution Heritable changes in populations over generations Biology s core theme The scientific explanation for both 1 The unit of life 2 The diversity of life The word science is derived from the Latin word meaning to know Science is both 1 Way of knowing 2 Body of knowledge Scientists use two main forms of inquiries 1 Discovery science which describes natural structures and processes 2 Hypothesis based science Observations lead to questions Questions lead to hypothesis Tentative answers to well framed questions Usually if then statements Tested by observation or experimentation Should be specific Example One of Hypothesis Based Science Testing which has the most air resistance between a Publix bag yellow parachute or a green tissue paper Hypothesis The heavy yellow plastic parachute will have the most air resistance Testing Publix bag 2 4 seconds Yellow parachute 2 seconds Green tissue paper 1 3 seconds Conclusion The Publix bag has the most air resistance Example Two of Hypothesis Based Science Flashlight isn t working Hypothesis 1 Dead batteries Hypothesis 2 Burnt out bulb Conclusion Once the batteries were changed the flashlight still did not work Once the light bulb was changed the flashlight began to work again Failure to falsify a hypothesis does not prove it Ex Replace bulb It now works Supports the hypothesis that the light bulb was burnt out but does not prove it Perhaps the first bulb was inserted incorrectly Scientific Method Example Cholera outbreak in London in 1854 Scientists 1 Did not know what caused Cholera 2 Did not know how Cholera was spread 3 Did know that Cholera was deadly Observation Dr John Snow observed that most cases of Cholera were located near a water pump on Broadway Street Cholera affected the digestive tract causing severe diarrhea Residents who drank from the pump contracted Cholera Visitors who drank from the pump contracted Cholera People who drank beer not water did not get Cholera Hypothesis A hypothesis is a tentative explanation for an observation What would be an acceptable hypothesis for the observations made by Dr Snow 1 The process of making beer cleaned the water making it free of Cholera Results Now it is known that Cholera Is caused by a bacteria that lives in feces The bacteria is spread through unsafe sanitary conditions water Death are due to severe dehydration from diarrhea Chapter Two Biology Notes August 29th 2012 Elements and Atoms An element is substance which cannot be broken down into other substances by chemical reactions 92 naturally occurring elements totaled 103 Atom is the smallest unit of an element that has all of its properties Elements in Organisms Most common Hydrogen Carbon Nitrogen Oxygen Phosphorus Sulfur Others Calcium Iron Sodium Potassium Magnesium Trace elements are essential for life An iodine efficiency and sometimes causes gotters Fluoride in the Water There has been a sharp decline in tooth decay in the last few decades Flouride containing chemicals have been added to drinking water Some elements such as cadium is harmful This element is found in kid toys Subatomic Particles in Atoms Protons positively charged Neutrons no charge Electron negative charge Characteristics of Atoms Protons and neutrons are found in the nucleus Electrons orbit the nucleus Elements differ in the number of subatomic particles in their atoms The number of protons atomic number determines which element it is An atoms mass number often called atomic weight is the number of protons neutrons with neutral atom Know the difference between atomic number and atomic weight Neutral atom Number of electrons number of protons Isotopes of an Element Contain Different Number of Neutrons Element Atomic Number Atomic Weight H 1 1 2 1 3 1 C 6 12 6 13 6 14 Radio Active Isotopes Nucleus decays giving off particles and energy Uncontrolled exposure to radioactivity can harm living organisms by damaging DNA Example April 26 1986 Chemobyl nuclear accident Things can go wrong with nuclear power plants Only isotopic atoms can decay There are nuclear power plants in Alabama