Lecture Chapter 1 Intro themes in the study of life What is biology o The scientific study of life Life is recognized by what living things do Some properties of life o Order regulation energy processing growth and development reproduction response to the environment evolutionary adaptation Themes connect the concepts of biology o Help organize biological information Life can be studied at different levels from molecules to the entire living planet The study of life can be divided into different levels of biological organization Emergent properties results from the arrangement and interaction of parts within a system o Emergent properties characterize nonbiological entities as well Sum is greater than the parts Power and limitations of reductionism o Reductionism is the reduction of complex systems to simpler components that are more manageable the study o An understanding of biological balances Systems biology o A system is a combination of components that function together o System biology constructs models for the dynamic behavior of whole biological systems Models are representations of natural phenomena and can take the form of o Diagrams 3 D objects computer programs math equations Organisms interact with their environment exchanging matter and energy Structure and function are correlated at all levels of biological organization o Are closely related Cells are an organism s basic units of structure and function o The cell is the lowest level of organization that can perform all activities required for life o All cells Are enclosed by a membrane Use DNA as their genetic information The ability of a cell to divide is the basis of all The continuity of life is based on heritable info In the form of DNA o Chromosomes contain most of a cells genetic material in the form of DNA o DNA is the substance of genes o Genes are the units of inheritance that transmit info From parent to offspring o Each chromosome has 1 long DNA molecule with hundreds thousands of genes Feedback mechanisms regulate biological systems o Allow biological processes to self regulate o Negative feedback means that as more of a product accumulates the process that creates it slows down and less of the product is produced o Positive feedback means that as more of a product accumulates the process that creates it speeds up and more of the product is produced Evolution o o o nothing in Biology makes sense except in the light of evolution Evolution unifies biology at different scales of size throughout the history of life on Earth Approximately 1 8 million species have been identified and named to date and thousands more or identified each year 3 domains of life o The 3 domain system is currently used and replaces the old 5 kingdom system Domain Archea Domain Eukarya Domain Protists Unity in the o A striking unity underlies the diversity of life for ex DNA is the universal genetic language common to all organisms Unity is evident in many features of cell structure o Darwins Scientists use 2 main form of inquiry in their study of nature o The word science is derived from Latin and means to know o Inquiry is the search of information and explanation o There are 2 main types of scientific inquiry Discovery science Describes natural structures and processes This approach is based on observation and the analysis of data Hypothesis based science Types of data o Data are recorded observations or items of info o Data fall into 2 categories Qualitative or descriptions rather than measurements Quantitative or recorded measurements which are sometimes organized into tables and graphs Induction in Discovery science o Inductive reasoning draws conclusions through the logical process of induction o Repeat specific observations can lead to important generalizations ex sun always rises in the east o Observations can lead us to ask questions and propose hypothetical explanations based on hypothesis The role of hypothesis o A hypothesis is a tentative answer to a well framed question o A scientific Deduction the If then o Deductive reasoning uses general premises to make specific predictions A closer look at hypothesis o A hypothesis must be testable and falsifiable o Hypothesis based science often makes use of 2 or more alternative hypothesis o Failure to falsify a hypothesis does not prove its right The myth of the scientific method o Is an idealized process of inquiry o Hypothesis based science is based on the textbook scientific method but rarely follows all the ordered steps Designed controlled experiments o A controlled experiment compares an experimental group with a control group o Ideally only the variable of interest differs between the control and experimental groups o A controlled experiment means that control groups are used to cancel the effects of unwanted variables o A controlled experiment doesn t mean that all unwanted variables are kept constant Limitations of science o In science observations and experimental results must be repeatable o Science can t support Theories of science o In the context of science a theory is Broader scope than a hypothesis General and can lead to new testable hypothesis Supported by a large body of evidence in comparison to a hypothesis The culture of science o Most scientists work in teams which often include graduate and undergraduate students o Good communication is important in order to share results through seminars publications and websites Science technology and society o The goal of science is to understand natural phenomena o The goal of technology is to apply scientific knowledge for some specific purpose o Science and technology are interdependent o Biology is marked by discoveries technology marked by invensions Lecture Chapter 2 A chemical connection to biology o Biology is a multidisciplinary science o Living organisms are subject to basic laws of physics and chemistry Elements and compounds o Organisms are composed of matter which is anything that takes up space and has mass o Mater is made up of elements substances that can t be broken down to other substances Essential elements o Include Carbon Hydrogen Oxygen and Nitrogen CHON o Make up 96 of living matter A few other elements o Make up remaining 4 of living matter Phosphorus Calcium Sulfur Potassium Trace elements are still required by an organism Elements and Atoms o Each element Consists of a certain kind of atom that is different from those of other elements o An atom Is the smallest unit of matter that still
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