Unit 1_ Intro to Science and the Study of Life PDF

Chapter 1 The Science of Life Goal of Science To investigate and understand the natural world To explain events in the natural world To use those explanations to make useful predictions. How Science is Done When scientists do their work they follow a 5 step process called the scientif...

Chapter 1 The Science of Life Goal of Science To investigate and understand the natural world To explain events in the natural world To use those explanations to make useful predictions. How Science is Done When scientists do their work they follow a 5 step process called the scientific method Vocabulary of the Scientific Method Usually starts with an observation ▫ The process of gathering information about events or processes in a careful, orderly way. Data ▫ The information you collect from making observations Vocabulary of the Scientific Method Quantitative Data ▫ Data that are expressed as numbers, obtained by counting or measuring. Qualitative Data ▫ Data that descriptive and involve characteristics that can’t easily be measured. Vocabulary of the Scientific Method Quantitative VS. Qualitative The rollercoaster Those people look goes 50 mph like they are having fun Ten people threw up The cars are yellow after the ride There are 9 cars Vocabulary of the Scientific Method Inference ▫ A logical interpretation based on prior knowledge or experience. Hypothesis ▫ A proposed scientific explanation for a set of observations ▫ Hypotheses can be ruled out or supported Vocabulary of the Scientific Method A hypothesis has to be something that can be tested by running a controlled experiment ▫ Using controls when you test a hypothesis Variables ▫ The things that you change, keep the same, or measure when you are testing a hypothesis Vocabulary of the Scientific Method Independent (Manipulated) Variable ▫ The variable you change to see if it affects your answer. Dependent (responding) Variable ▫ The variable that changes in response to the independent variable Control ▫ Something you keep the same so you can test your independent variable How Science is Done Scientific method. 1. Ask a question 2. Form a (testable) hypothesis or educated guess 3. Conduct a controlled experiment (to test the hypothesis) 4. Record & analyze results 5. Develop a conclusion🡪 Use the data from the experiment to see if it supports your hypothesis Science is a Process Keep asking questions and testing and re-testing hypotheses (repetition) until they are very strongly supported or discredited. If supported well enough a hypothesis may become a theory ▫ A well tested explanation that unifies a broad range of observations. What is Biology Biology is study of the living world (life and living things). What does it mean to say something is alive? All living things must have ALL of the following 8 characteristics to be considered alive. Characteristics of Living Things Living things are made up of units called cells. Living things reproduce. Characteristics of Living Things Living things are based on a universal genetic code called DNA. Living things grow & develop. Characteristics of Living Things Living things obtain and use materials and energy (metabolism). Living things respond to changing signals (stimuli) in the environment. Characteristics of Living Things Living things maintain a stable internal environment (maintain homeostasis) ▫ For example, Constant temp or pH As a group, living things change over time (Evolve). Characteristics of Living Things Metabolism ▫ Set of chemical reactions through which an organism builds up or breaks down materials as it carries out its life processes Reproduction ▫ Sexual – need two parents ▫ Asexual – need one parent Levels of Organization Atoms ▫ Smallest unit of living things Molecules ▫ Atoms that make up living things (C6H12O6) Cells ▫ Smallest working unit of life Tissues ▫ Groups of similar types of cells cells Organs ▫ Groups of different tissues that have a common function Organ Systems ▫ Several organs working together Organism ▫ Individual living things Levels of Organization Population ▫ Group of 1 type of organism living in the same place at the same time. Community ▫ Different populations living in the same place at the same time Ecosystem ▫ Community & its nonliving (abiotic) surroundings Levels of Organization Biomes ▫ Ecosystems that have the same climate (e.g., desert, tundra, rainforest) Biosphere ▫ The layer of life around the Earth that contains all the biomes Levels of Organization