Ch 1 Intro Lecture - Copy (1) Biology Lecture Notes PDF

“The beginning is always today.” Mary Shelly 1  Ch. 1: The Study of Life Biology: The scientific study of living organisms, -and their interactions with each other and the environment. Hightower Biol 1107 Glacier Nat. P...

“The beginning is always today.” Mary Shelly 1  Ch. 1: The Study of Life Biology: The scientific study of living organisms, -and their interactions with each other and the environment. Hightower Biol 1107 Glacier Nat. Park, Montana 2016 F24 2 What is life? What do living things do? 3 7 to 9 Properties of Life Maintains Order Response to the environment Evolution/adaptation Reproduction Regulation/Homestasis Energy processing Growth and development 4  Levels of Biological Organization The biosphere Tissues Ecosystems Organs and organ systems Communities Cells Organelles Organisms Atoms Populations Molecules 5 The Cell is an Organism’s Basic Unit of Structure and Function The cell is the lowest level of organization that can perform all activities required for life Eukaryotic cells: have membrane-enclosed organelles including a nucleus Prokaryotic cells: do not contain a nucleus or other membrane-enclosed organelles Organelle: cellular structure with a special function 6  Prokaryotic cell Eukaryotic cell DNA (no nucleus) Membrane Membrane Cytoplasm Nucleus (membrane- enclosed) Membrane- DNA (throughout enclosed organelles nucleus) 1 m 7  Nucleus A DNA C Nucleotide T A T Cell A C C G T A G T A (a) DNA double helix (b) Single strand of DNA 8 Classifying the Diversity of Life # Sp. On Earth? – Estimates range from 10 to 100 million? – 1.8 million identified to date? Domains are the broadest units of classification 9  Comparisons of genetics and structure of the three domains Characteristic Bacteria Archaea Eukarya Membrane-bound No No Yes nucleus Circular DNA Yes Yes No Histones No Yes Yes Peptidoglycan Yes No No Membrane lipids Ester-linked Ether-linked Ester-linked Ribosome mass 70s 70s 80s Chloramphenicol Sensitive Resistant Resistant Growth above 80C Yes Yes No Growth above 100C No Yes No 10 (a) Domain Bacteria (b) Domain Archaea 2 m 2 m (c) Domain Eukarya Kingdom Animalia 100 m Kingdom Plantae Protists Kingdom Fungi 11  Species Genus Family Order Class Phylum Kingdom Domain Ursus americanus (American black bear) Ursus Ursidae Carnivora Mammalia Taxonomical Hierarcy Chordata Animalia Eukarya 12 Two main pathways of scientific study Descriptive science: attempts to describe nature; observe, explore, discover Hypothesis based science: attempts to explain nature, uses scientific method 13 Types of Data in science Data: recorded observations or items of information Data fall into two categories – Qualitative, or descriptions rather than measurements NaCl is present in the sample – Quantitative, or recorded measurements The sample is 40% NaCl 14 Hypothesis based science: aka, the Scientific Method Hypothesis: a tentative answer to a well-framed question http://www.ideachampions.com/weblogs/strange-albert- einstein.jpg 15 Hypothesis based science: aka, the Scientific Method Observation Question Hypothesis Prediction Experiment/Test Result 16  For example, – Observation: Your phone doesn’t work – Question: Why doesn’t your phone work? – Hypothesis: The battery is dead. The hypothesis must be testable so it is rewritten into a predictive statement that can be shown to be false. 17  For example, – Observation: Your phone doesn’t work – Question: Why doesn’t your phone work? – Hypothesis: The battery is dead. – Prediction: Charging the battery will make the phone work. (If I charge the battery, then the phone will work.) The prediction must be testable. It must be possible for potential results to show the prediction is false. 18  For example, – Observation: Your phone doesn’t work – Question: Why doesn’t your phone work? – Hypothesis: The battery is dead. – Prediction: Charging the battery will make the phone work. – Test: Charge the battery. – Results: The phone now works. The test did not falsify the hypothesis. 19  Failure to reject/falsify a hypothesis does not prove that hypothesis is correct – For example, you charge your phone’s battery, and it now works; this supports the hypothesis that your battery was dead, but does not prove it. 20 Questions That Can and Cannot Be Addressed by Science A hypothesis must be testable and falsifiable Supernatural and religious explanations are outside the bounds of science 21 22  Controlled Experiments A controlled experiment compares an experimental group with a control group Ideally, only one variable differs between the control and experimental groups Independent vs. Dependent variable 23 Exploration of the Openstax Text: Ch 1 A person who won’t read has no advantage over one who can’t read. -READ the following sections: Introduction, Science of Biology, Scientific Reasoning, The scientific method, Reporting Scientific work (you will need this later in the course), Properties of life, Levels of Organization of living things, Diversity of Life 24 Ch 1: Review 25  Ch 1: Review Questions to think about What is biology List and discuss the properties of life. What does it mean to be alive? List the levels of biological organization in order from smaller to larger. List the hierarchy of taxonomy in order from most inclusive to least inclusive. What do all cells have in common? What are the two main types of cells and what distinguishes each of them? What types of life forms have each cell type? What are the three Domains of life? What are the differences between these three domains? What is the difference between the goals of Descriptive and Hypothesis based science? Describe the difference between qualitative and quantitative data. Give examples of each. List the steps of the scientific method. Why must a hypothesis and prediction be testable? Can you ever prove a hypothesis to be correct? Why or why not? What is plagiarism? What is a controlled experiment? When graphically displaying data from a controlled experiment, upon which axis does one place the independent variable? The dependent variable? 26